1
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Eriksson A, Kawde A, Hrachowina L, McKibbin SR, Shi Q, Borgström MT, Wågberg T, Pullerits T, Uhlig J. Synthesis of Well-Ordered Functionalized Silicon Microwires Using Displacement Talbot Lithography for Photocatalysis. ACS OMEGA 2024; 9:20623-20628. [PMID: 38737027 PMCID: PMC11079887 DOI: 10.1021/acsomega.4c03039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 05/14/2024]
Abstract
Metal-assisted chemical etching (MACE) is a cheap and scalable method that is commonly used to obtain silicon nano- or microwires but lacks spatial control. Herein, we present a synthesis method for producing vertical and highly periodic silicon microwires, using displacement Talbot lithography before wet etching with MACE. The functionalized periodic silicon microwires show 65% higher PEC performance and 2.3 mA/cm2 higher net photocurrent at 0 V compared to functionalized, randomly distributed microwires obtained by conventional MACE at the same potentials.
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Affiliation(s)
- Axl Eriksson
- Chemical
Physics, Department of Chemistry, Lund University, Kemicentrum Naturvetarevägen
16, Lund 223 62, Sweden
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
| | - Anurag Kawde
- Chemical
Physics, Department of Chemistry, Lund University, Kemicentrum Naturvetarevägen
16, Lund 223 62, Sweden
- Lund
Institute of Advanced Neutron and X-ray Science, Lund University, Scheelevägen 19, Lund 223 70, Sweden
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
| | - Lukas Hrachowina
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
- Solid
State Physics, Department of Physics, Lund
University, Professorsgatan 1, Lund 223 63, Sweden
| | - Sarah R. McKibbin
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
- Solid
State Physics, Department of Physics, Lund
University, Professorsgatan 1, Lund 223 63, Sweden
| | - Qi Shi
- Chemical
Physics, Department of Chemistry, Lund University, Kemicentrum Naturvetarevägen
16, Lund 223 62, Sweden
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
| | - Magnus T. Borgström
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
- Solid
State Physics, Department of Physics, Lund
University, Professorsgatan 1, Lund 223 63, Sweden
| | - Thomas Wågberg
- Department
of Physics, Umeå University, Linnaeus väg 20, Umeå 907 36, Sweden
- Wallenberg
Initiative Materials Science for Sustainability, Department of Physics, Umeå University, Umeå 901 87, Sweden
| | - Tönu Pullerits
- Chemical
Physics, Department of Chemistry, Lund University, Kemicentrum Naturvetarevägen
16, Lund 223 62, Sweden
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
| | - Jens Uhlig
- Chemical
Physics, Department of Chemistry, Lund University, Kemicentrum Naturvetarevägen
16, Lund 223 62, Sweden
- Lund
Institute of Advanced Neutron and X-ray Science, Lund University, Scheelevägen 19, Lund 223 70, Sweden
- NanoLund,
Department of Physics, Lund University, Professorsgatan 1, Lund 223 63, Sweden
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2
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Oliva M, Kaganer V, Pudelski M, Meister S, Tahraoui A, Geelhaar L, Brandt O, Auzelle T. A route for the top-down fabrication of ordered ultrathin GaN nanowires. NANOTECHNOLOGY 2023; 34:205301. [PMID: 36745915 DOI: 10.1088/1361-6528/acb949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
We introduce a facile route for the top-down fabrication of ordered arrays of GaN nanowires with aspect ratios exceeding 10 and diameters below 20 nm. Highly uniform thin GaN nanowires are first obtained by lithographic patterning a bilayer Ni/SiNxhard mask, followed by a combination of dry and wet etching in KOH. The SiNxis found to work as an etch stop during wet etching, which eases reproducibility. Arrays with nanowire diameters down to (33 ± 5) nm can be achieved with a uniformity suitable for photonic applications. Next, a scheme for digital etching is demonstrated to further reduce the nanowire diameter down to 5 nm. However, nanowire breaking or bundling is observed for diameters below ≈20 nm, an effect that is associated to capillary forces acting on the nanowires during sample drying in air. Explicit calculations of the nanowire buckling states under capillary forces indicate that nanowire breaking is favored by the incomplete wetting of water on the substrate surface during drying. The observation of intense nanowire photoluminescence at room-temperature indicates good compatibility of the fabrication route with optoelectronic applications. The process can be principally applied to any GaN/SiNxnanostructures and allows regrowth after removal of the SiNxmask.
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Affiliation(s)
- M Oliva
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - V Kaganer
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - M Pudelski
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - S Meister
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - A Tahraoui
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - L Geelhaar
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - O Brandt
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
| | - T Auzelle
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117 Berlin, Germany
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3
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Cameron D, Coulon PM, Fairclough S, Kusch G, Edwards PR, Susilo N, Wernicke T, Kneissl M, Oliver RA, Shields PA, Martin RW. Core-Shell Nanorods as Ultraviolet Light-Emitting Diodes. NANO LETTERS 2023; 23:1451-1458. [PMID: 36748796 PMCID: PMC9951243 DOI: 10.1021/acs.nanolett.2c04826] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Existing barriers to efficient deep ultraviolet (UV) light-emitting diodes (LEDs) may be reduced or overcome by moving away from conventional planar growth and toward three-dimensional nanostructuring. Nanorods have the potential for enhanced doping, reduced dislocation densities, improved light extraction efficiency, and quantum wells free from the quantum-confined Stark effect. Here, we demonstrate a hybrid top-down/bottom-up approach to creating highly uniform AlGaN core-shell nanorods on sapphire repeatable on wafer scales. Our GaN-free design avoids self-absorption of the quantum well emission while preserving electrical functionality. The effective junctions formed by doping of both the n-type cores and p-type caps were studied using nanoprobing experiments, where we find low turn-on voltages, strongly rectifying behaviors and significant electron-beam-induced currents. Time-resolved cathodoluminescence measurements find short carrier liftetimes consistent with reduced polarization fields. Our results show nanostructuring to be a promising route to deep-UV-emitting LEDs, achievable using commercially compatible methods.
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Affiliation(s)
- Douglas Cameron
- Department
of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - Pierre-Marie Coulon
- Department
of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, United Kingdom
- Centre
de Recherche sur l’Hétéro-Epitaxie et ses Applications
(CRHEA)−Centre National de la Recherche Scientifique (CNRS), Rue Bernard Grégory, 06560 Valbonne, France
| | - Simon Fairclough
- Department
of Materials Science and Metallurgy, University
of Cambridge, CB3 OFS Cambridge, United Kingdom
| | - Gunnar Kusch
- Department
of Materials Science and Metallurgy, University
of Cambridge, CB3 OFS Cambridge, United Kingdom
| | - Paul R. Edwards
- Department
of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - Norman Susilo
- Institute
of Solid State Physics, Technische Universität
Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Tim Wernicke
- Institute
of Solid State Physics, Technische Universität
Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Michael Kneissl
- Institute
of Solid State Physics, Technische Universität
Berlin, Hardenbergstraße 36, 10623 Berlin, Germany
| | - Rachel A. Oliver
- Department
of Materials Science and Metallurgy, University
of Cambridge, CB3 OFS Cambridge, United Kingdom
| | - Philip A. Shields
- Department
of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, United Kingdom
| | - Robert W. Martin
- Department
of Physics, Scottish Universities Physics Alliance (SUPA), University of Strathclyde, Glasgow G4 0NG, United Kingdom
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4
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Lohr LM, Ciesielski R, Glabisch S, Schröder S, Brose S, Soltwisch V. Nanoscale grating characterization using EUV scatterometry and soft x-ray scattering with plasma and synchrotron radiation. APPLIED OPTICS 2023; 62:117-132. [PMID: 36606857 DOI: 10.1364/ao.475566] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
Modern semiconductor structures reach sizes in the nanometer regime. Optical metrology characterizes test structures for the quality assessment of semiconductor fabrication. The limits of radiation to resolve nanometer structure sizes can be overcome by shortening the wavelength. The compact source extreme ultraviolet (EUV) scatterometer presented here characterizes samples in the EUV spectral range using plasma radiation. Reference measurements with synchrotron radiation are carried out using a beamline scatterometer. A comparison including Markov chain Monte Carlo sampling shows that the compact source and beamline setups can both determine the given dimensional parameters of a nanoscale grating with uncertainties in the sub-nanometer range. Grating characterization based on soft x ray scattering has increased accuracy.
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5
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Jonker D, Berenschot EJW, Tas NR, Tiggelaar RM, van Houselt A, Gardeniers HJGE. Large Dense Periodic Arrays of Vertically Aligned Sharp Silicon Nanocones. NANOSCALE RESEARCH LETTERS 2022; 17:100. [PMID: 36245035 PMCID: PMC9573847 DOI: 10.1186/s11671-022-03735-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Convex cylindrical silicon nanostructures, also referred to as silicon nanocones, find their value in many applications ranging from photovoltaics to nanofluidics, nanophotonics, and nanoelectronic applications. To fabricate silicon nanocones, both bottom-up and top-down methods can be used. The top-down method presented in this work relies on pre-shaping of silicon nanowires by ion beam etching followed by self-limited thermal oxidation. The combination of pre-shaping and oxidation obtains high-density, high aspect ratio, periodic, and vertically aligned sharp single-crystalline silicon nanocones at the wafer-scale. The homogeneity of the presented nanocones is unprecedented and may give rise to applications where numerical modeling and experiments are combined without assumptions about morphology of the nanocone. The silicon nanocones are organized in a square periodic lattice, with 250 nm pitch giving arrays containing 1.6 billion structures per square centimeter. The nanocone arrays were several mm2 in size and located centimeters apart across a 100-mm-diameter single-crystalline silicon (100) substrate. For single nanocones, tip radii of curvature < 3 nm were measured. The silicon nanocones were vertically aligned, baring a height variation of < 5 nm (< 1%) for seven adjacent nanocones, whereas the height inhomogeneity is < 80 nm (< 16%) across the full wafer scale. The height inhomogeneity can be explained by inhomogeneity present in the radii of the initial columnar polymer mask. The presented method might also be applicable to silicon micro- and nanowires derived through other top-down or bottom-up methods because of the combination of ion beam etching pre-shaping and thermal oxidation sharpening. A novel method is presented where argon ion beam etching and thermal oxidation sharpening are combined to tailor a high-density single-crystalline silicon nanowire array into a vertically aligned single-crystalline silicon nanocones array with < 3 nm apex radius of curvature tips, at the wafer scale.
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Affiliation(s)
- Dirk Jonker
- Mesoscale Chemical Systems, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
- Physics of Interfaces and Nanomaterials, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
| | - Erwin J W Berenschot
- Mesoscale Chemical Systems, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Niels R Tas
- Mesoscale Chemical Systems, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Roald M Tiggelaar
- NanoLab Cleanroom, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Arie van Houselt
- Physics of Interfaces and Nanomaterials, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands
| | - Han J G E Gardeniers
- Mesoscale Chemical Systems, University of Twente, MESA+ Institute, P.O. Box 217, 7500 AE, Enschede, The Netherlands
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6
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Valderas-Gutiérrez J, Davtyan R, Sivakumar S, Anttu N, Li Y, Flatt P, Shin JY, Prinz CN, Höök F, Fioretos T, Magnusson MH, Linke H. Enhanced Optical Biosensing by Aerotaxy Ga(As)P Nanowire Platforms Suitable for Scalable Production. ACS APPLIED NANO MATERIALS 2022; 5:9063-9071. [PMID: 35909504 PMCID: PMC9315950 DOI: 10.1021/acsanm.2c01372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Sensitive detection of low-abundance biomolecules is central for diagnostic applications. Semiconductor nanowires can be designed to enhance the fluorescence signal from surface-bound molecules, prospectively improving the limit of optical detection. However, to achieve the desired control of physical dimensions and material properties, one currently uses relatively expensive substrates and slow epitaxy techniques. An alternative approach is aerotaxy, a high-throughput and substrate-free production technique for high-quality semiconductor nanowires. Here, we compare the optical sensing performance of custom-grown aerotaxy-produced Ga(As)P nanowires vertically aligned on a polymer substrate to GaP nanowires batch-produced by epitaxy on GaP substrates. We find that signal enhancement by individual aerotaxy nanowires is comparable to that from epitaxy nanowires and present evidence of single-molecule detection. Platforms based on both types of nanowires show substantially higher normalized-to-blank signal intensity than planar glass surfaces, with the epitaxy platforms performing somewhat better, owing to a higher density of nanowires. With further optimization, aerotaxy nanowires thus offer a pathway to scalable, low-cost production of highly sensitive nanowire-based platforms for optical biosensing applications.
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Affiliation(s)
- Julia Valderas-Gutiérrez
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Rubina Davtyan
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Sudhakar Sivakumar
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Nicklas Anttu
- Physics,
Faculty of Science and Engineering, Åbo
Akademi University, Henrikinkatu
2, FI-20500 Turku, Finland
| | - Yuyu Li
- AlignedBio
AB, Medicon Village,
Scheeletorget 1, SE-22363, Lund 22100, Sweden
| | - Patrick Flatt
- AlignedBio
AB, Medicon Village,
Scheeletorget 1, SE-22363, Lund 22100, Sweden
| | - Jae Yen Shin
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Christelle N. Prinz
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Fredrik Höök
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Department
of Physics, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Thoas Fioretos
- Division
of Clinical Genetics, Lund University, SE-22185 Lund, Sweden
| | - Martin H. Magnusson
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Heiner Linke
- NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
- Division
of Solid State Physics, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
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7
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López-Fraguas E, Binkowski F, Burger S, Hagedorn S, García-Cámara B, Vergaz R, Becker C, Manley P. Tripling the light extraction efficiency of a deep ultraviolet LED using a nanostructured p-contact. Sci Rep 2022; 12:11480. [PMID: 35798778 PMCID: PMC9262900 DOI: 10.1038/s41598-022-15499-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022] Open
Abstract
Despite a wide array of applications, deep ultra-violet light emitting diodes offer relatively poor efficiencies compared to their optical counterparts. A contributing factor is the lower light extraction efficiency due to both highly absorbing p-contacts and total internal reflection. Here, we propose a structure consisting of a hexagonal periodic array of cylindrical nanoholes in the multi-layered p-contact which are filled with platinum. This nanostructure reduces the absorption of the p-contact layer, leading to a higher emission into the n-contact compared to a planar reference. An optimum geometry of the nanostructure allows a light extraction efficiency of 15.0%, much higher than the typical 4.6% of a planar reference. While the nanostructure strongly decreases the light absorption in the p-contact, it is still not able to considerably reduce the total internal reflection. Consequently, the nanostructured p-contact should be combined with other optical strategies, such as nanopatterned sapphire substrates to increase the efficiency even further. Despite this, the nanostructure described in this work provides a readily realizable path to enhancing the light extraction efficiency of state-of-the-art deep ultra-violet light emitting diodes.
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Affiliation(s)
- Eduardo López-Fraguas
- GDAF-UC3M, Dep. Tecnología Electrónica, Universidad Carlos III de Madrid, Avda. Universidad, 30., 28911, Leganés, Madrid, Spain
| | - Felix Binkowski
- Zuse Institute Berlin, Berlin, Takustraße 7, 14195, Berlin, Germany
| | - Sven Burger
- Zuse Institute Berlin, Berlin, Takustraße 7, 14195, Berlin, Germany
- JCMwave GmbH, Bolivarallee 22, 14050, Berlin, Germany
| | - Sylvia Hagedorn
- Ferdinand-Braun-Institut (FBH), Gustav-Kirchhoff-Str. 4, 12489, Berlin, Germany
| | - Braulio García-Cámara
- GDAF-UC3M, Dep. Tecnología Electrónica, Universidad Carlos III de Madrid, Avda. Universidad, 30., 28911, Leganés, Madrid, Spain
| | - Ricardo Vergaz
- GDAF-UC3M, Dep. Tecnología Electrónica, Universidad Carlos III de Madrid, Avda. Universidad, 30., 28911, Leganés, Madrid, Spain
| | - Christiane Becker
- Department Optics for Solar Energy, Helmholtz Zentrum Berlin für Materialen und Energie, Kekuléstr. 5, 12489, Berlin, Germany
| | - Phillip Manley
- Zuse Institute Berlin, Berlin, Takustraße 7, 14195, Berlin, Germany.
- JCMwave GmbH, Bolivarallee 22, 14050, Berlin, Germany.
- Department Optics for Solar Energy, Helmholtz Zentrum Berlin für Materialen und Energie, Kekuléstr. 5, 12489, Berlin, Germany.
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8
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Carthew J, Taylor JBJ, Garcia-Cruz MR, Kiaie N, Voelcker NH, Cadarso VJ, Frith JE. The Bumpy Road to Stem Cell Therapies: Rational Design of Surface Topographies to Dictate Stem Cell Mechanotransduction and Fate. ACS APPLIED MATERIALS & INTERFACES 2022; 14:23066-23101. [PMID: 35192344 DOI: 10.1021/acsami.1c22109] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cells sense and respond to a variety of physical cues from their surrounding microenvironment, and these are interpreted through mechanotransductive processes to inform their behavior. These mechanisms have particular relevance to stem cells, where control of stem cell proliferation, potency, and differentiation is key to their successful application in regenerative medicine. It is increasingly recognized that surface micro- and nanotopographies influence stem cell behavior and may represent a powerful tool with which to direct the morphology and fate of stem cells. Current progress toward this goal has been driven by combined advances in fabrication technologies and cell biology. Here, the capacity to generate precisely defined micro- and nanoscale topographies has facilitated the studies that provide knowledge of the mechanotransducive processes that govern the cellular response as well as knowledge of the specific features that can drive cells toward a defined differentiation outcome. However, the path forward is not fully defined, and the "bumpy road" that lays ahead must be crossed before the full potential of these approaches can be fully exploited. This review focuses on the challenges and opportunities in applying micro- and nanotopographies to dictate stem cell fate for regenerative medicine. Here, key techniques used to produce topographic features are reviewed, such as photolithography, block copolymer lithography, electron beam lithography, nanoimprint lithography, soft lithography, scanning probe lithography, colloidal lithography, electrospinning, and surface roughening, alongside their advantages and disadvantages. The biological impacts of surface topographies are then discussed, including the current understanding of the mechanotransductive mechanisms by which these cues are interpreted by the cells, as well as the specific effects of surface topographies on cell differentiation and fate. Finally, considerations in translating these technologies and their future prospects are evaluated.
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Affiliation(s)
- James Carthew
- Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jason B J Taylor
- Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Maria R Garcia-Cruz
- Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Nasim Kiaie
- Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Nicolas H Voelcker
- Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
- Melbourne Centre for Nanofabrication, Victorian Node of the Australian National Fabrication Facility, Clayton, Victoria 3168, Australia
- Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
- ARC Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, Victoria 3800, Australia
- CSIRO Manufacturing, Bayview Avenue, Clayton, VIC 3168, Australia
| | - Victor J Cadarso
- Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria 3800, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Victoria 3800, Australia
| | - Jessica E Frith
- Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
- ARC Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, Victoria 3800, Australia
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia
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9
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Jonker D, Jafari Z, Winczewski JP, Eyovge C, Berenschot JW, Tas NR, Gardeniers JGE, De Leon I, Susarrey-Arce A. A wafer-scale fabrication method for three-dimensional plasmonic hollow nanopillars. NANOSCALE ADVANCES 2021; 3:4926-4939. [PMID: 34485816 PMCID: PMC8386417 DOI: 10.1039/d1na00316j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Access to nanofabrication strategies for crafting three-dimensional plasmonic structures is limited. In this work, a fabrication strategy to produce 3D plasmonic hollow nanopillars (HNPs) using Talbot lithography and I-line photolithography is introduced. This method is named subtractive hybrid lithography (SHL), and permits intermixed usage of nano-and-macroscale patterns. Sputter-redeposition of gold (Au) on the SHL resist pattern yields large areas of dense periodic Au-HNPs. These Au-HNPs are arranged in a square unit cell with a 250 nm pitch. The carefully controlled fabrication process resulted in Au-HNPs with nanoscale dimensions over the Au-HNP dimensions such as an 80 ± 2 nm thick solid base with a 133 ± 4 nm diameter, and a 170 ± 10 nm high nano-rim with a 14 ± 3 nm sidewall rim-thickness. The plasmonic optical response is assessed with FDTD-modeling and reveals that the highest field enhancement is at the top of the hollow nanopillar rim. The modeled field enhancement factor (EF) is compared to the experimental analytical field enhancement factor, which shows to pair up with ca. 103 < EF < 104 and ca. 103 < EF < 105 for excitation wavelengths of 633 and 785 nm. From a broader perspective, our results can stimulate the use of Au-HNPs in the fields of plasmonic sensors and spectroscopy.
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Affiliation(s)
- D Jonker
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - Z Jafari
- School of Engineering and Sciences, Tecnologico de Monterrey Monterrey Nuevo Leon 64849 Mexico
| | - J P Winczewski
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - C Eyovge
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - J W Berenschot
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - N R Tas
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - J G E Gardeniers
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
| | - I De Leon
- School of Engineering and Sciences, Tecnologico de Monterrey Monterrey Nuevo Leon 64849 Mexico
| | - A Susarrey-Arce
- Mesoscale Chemical Systems, MESA+ Institute, University of Twente PO. Box 217 Enschede 7500AE The Netherlands
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10
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Chausse P, Shields P. Spatial periodicities inside the Talbot effect: understanding, control and applications for lithography. OPTICS EXPRESS 2021; 29:27628-27639. [PMID: 34615175 DOI: 10.1364/oe.431698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
Displacement Talbot Lithography (DTL) is a simple patterning technique for creating periodic sub-micron features on wafer areas up to 200 mm diameter for applications in, for example, plasmonic, photonic crystals, and metamaterials. It exploits the diffraction and interference generally avoided in classical lithography. The Talbot effect, on which DTL is based, is the periodic spatial repetition of a periodic mask illuminated by coherent light. The modelling of this phenomenon is essential to fully understand and predict the interference pattern obtained; for mask periods greater than twice the wavelength, new spatial periodicities are generally introduced that are smaller than the Talbot length. This study reports simulations of multiple 1D masks to explain the influence of these smaller spatial periodicities on the Talbot effect. By changing the mask configuration, one can tailor the spatial periodicity contributions and thus, control the feature size, uniformity, and contrast for Talbot-effect-based lithography.
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11
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Demontis V, Zannier V, Sorba L, Rossella F. Surface Nano-Patterning for the Bottom-Up Growth of III-V Semiconductor Nanowire Ordered Arrays. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2079. [PMID: 34443910 PMCID: PMC8398085 DOI: 10.3390/nano11082079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/07/2021] [Accepted: 08/10/2021] [Indexed: 12/18/2022]
Abstract
Ordered arrays of vertically aligned semiconductor nanowires are regarded as promising candidates for the realization of all-dielectric metamaterials, artificial electromagnetic materials, whose properties can be engineered to enable new functions and enhanced device performances with respect to naturally existing materials. In this review we account for the recent progresses in substrate nanopatterning methods, strategies and approaches that overall constitute the preliminary step towards the bottom-up growth of arrays of vertically aligned semiconductor nanowires with a controlled location, size and morphology of each nanowire. While we focus specifically on III-V semiconductor nanowires, several concepts, mechanisms and conclusions reported in the manuscript can be invoked and are valid also for different nanowire materials.
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Affiliation(s)
- Valeria Demontis
- NEST, Scuola Normale Superiore and Istituto Nanoscienze CNR, Piazza S. Silvestro 12, 56127 Pisa, Italy; (V.Z.); (L.S.)
| | - Valentina Zannier
- NEST, Scuola Normale Superiore and Istituto Nanoscienze CNR, Piazza S. Silvestro 12, 56127 Pisa, Italy; (V.Z.); (L.S.)
| | - Lucia Sorba
- NEST, Scuola Normale Superiore and Istituto Nanoscienze CNR, Piazza S. Silvestro 12, 56127 Pisa, Italy; (V.Z.); (L.S.)
| | - Francesco Rossella
- NEST, Scuola Normale Superiore and Istituto Nanoscienze CNR, Piazza S. Silvestro 12, 56127 Pisa, Italy; (V.Z.); (L.S.)
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy
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12
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Mauser KW, Solà-Garcia M, Liebtrau M, Damilano B, Coulon PM, Vézian S, Shields PA, Meuret S, Polman A. Employing Cathodoluminescence for Nanothermometry and Thermal Transport Measurements in Semiconductor Nanowires. ACS NANO 2021; 15:11385-11395. [PMID: 34156820 PMCID: PMC8320239 DOI: 10.1021/acsnano.1c00850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
Thermal properties have an outsized impact on efficiency and sensitivity of devices with nanoscale structures, such as in integrated electronic circuits. A number of thermal conductivity measurements for semiconductor nanostructures exist, but are hindered by the diffraction limit of light, the need for transducer layers, the slow scan rate of probes, ultrathin sample requirements, or extensive fabrication. Here, we overcome these limitations by extracting nanoscale temperature maps from measurements of bandgap cathodoluminescence in GaN nanowires of <300 nm diameter with spatial resolution limited by the electron cascade. We use this thermometry method in three ways to determine the thermal conductivities of the nanowires in the range of 19-68 W/m·K, well below that of bulk GaN. The electron beam acts simultaneously as a temperature probe and as a controlled delta-function-like heat source to measure thermal conductivities using steady-state methods, and we introduce a frequency-domain method using pulsed electron beam excitation. The different thermal conductivity measurements we explore agree within error in uniformly doped wires. We show feasible methods for rapid, in situ, high-resolution thermal property measurements of integrated circuits and semiconductor nanodevices and enable electron-beam-based nanoscale phonon transport studies.
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Affiliation(s)
- Kelly W. Mauser
- Center
for Nanophotonics, NWO-Institute AMOLF, Amsterdam, 1098 XG, The Netherlands
| | | | - Matthias Liebtrau
- Center
for Nanophotonics, NWO-Institute AMOLF, Amsterdam, 1098 XG, The Netherlands
| | | | | | | | | | | | - Albert Polman
- Center
for Nanophotonics, NWO-Institute AMOLF, Amsterdam, 1098 XG, The Netherlands
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13
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Azizi B, Amini Sabegh Z, Mahmoudi M, Rasouli S. Tunneling-induced Talbot effect. Sci Rep 2021; 11:6827. [PMID: 33767249 PMCID: PMC7994822 DOI: 10.1038/s41598-021-86289-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 03/15/2021] [Indexed: 11/09/2022] Open
Abstract
We investigate the reforming of a plane wave into a periodic waveform in its propagation through a structural asymmetry four-level quantum dot molecule (QDM) system that is induced by an inter-dot tunneling process and present the resulting tunneling-induced Talbot effect. The tunneling process between two neighborhood dots is provided with the aid of a gate voltage. Using a periodic coupling field the response of the medium to the propagating plane probe beam becomes periodic. The needed periodic coupling field is generated with the interference of two coherent plane waves having a small angle and propagating almost parallel to the probe beam direction. In the presence of the tunneling effect of an electron between two adjacent QDs, for the probe beam propagating through the QDM system, the medium becomes transparent where the coupling fields interfere constructively. As a result, the spatial periodicity of the coupling field modulates the passing plane probe beam. We determine the minimum length of the QDM system to generate a periodic intensity profile with a visibility value equal to 1 for the probe field at the exit plane of the medium. It is also shown that by increasing the propagation length of the probe beam through the QDM medium, the profile of the maximum intensity areas becomes sharper. This feature is quantified by considering a sharpness factor for the intensity profile of the probe beam at the transverse plane. Finally, we investigate free space propagation of the induced periodic field and present the Talbot images of the tunneling-induced periodic patterns at different propagation distances for different values of the QDM medium lengths. The presented dynamically designing method of the periodic coherent intensity patterns might find applications in science and technology. For instance, in optical lithography, the need to use micro/nanofabricated physical transmission diffraction gratings, in which preparation of them is expensive and time-consuming, can be eliminated.
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Affiliation(s)
- Babak Azizi
- Department of Physics, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran
| | - Zahra Amini Sabegh
- Department of Physics, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran
| | - Mohammad Mahmoudi
- Department of Physics, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran.
| | - Saifollah Rasouli
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), 45137-66731, Zanjan, Iran.
- Optics Research Center, Institute for Advanced Studies in Basic Sciences (IASBS), 45137-66731, Zanjan, Iran.
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14
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Strain-induced yellow to blue emission tailoring of axial InGaN/GaN quantum wells in GaN nanorods synthesized by nanoimprint lithography. Sci Rep 2021; 11:6754. [PMID: 33762623 PMCID: PMC7990954 DOI: 10.1038/s41598-021-86139-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/10/2021] [Indexed: 11/19/2022] Open
Abstract
GaN nanorods (NRds) with axial InGaN/GaN MQWs insertions are synthesized by an original cost-effective and large-scale nanoimprint-lithography process from an InGaN/GaN MQWs layer grown on c-sapphire substrates. By design, such NRds exhibit a single emission due to the c-axis MQWs. A systematic study of the emission of the NRds by time-resolved luminescence (TR-PL) and power dependence PL shows a diameter-controlled luminescence without significant degradation of the recombination rate thanks to the diameter-controlled strain tuning and QSCE. A blueshift up to 0.26 eV from 2.28 to 2.54 eV (543 nm to 488 nm) is observed for 3.2 nm thick InGaN/GaN QWs with an In composition of 19% when the NRds radius is reduced from 650 to 80 nm. The results are consistent with a 1-D based strain relaxation model. By combining state of the art knowledge of c-axis growth and the strong strain relieving capability of NRds, this process enables multiple and independent single-color emission from a single uniform InGaN/GaN MQWs layer in a single patterning step, then solving color mixing issue in InGaN based nanorods LED devices.
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15
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Coulon PM, Feng P, Wang T, Shields PA. Impact of Inductively Coupled Plasma Etching Conditions on the Formation of Semi-Polar ( 11 2 ¯ 2 ) and Non-Polar ( 11 2 ¯ 0 ) GaN Nanorods. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E2562. [PMID: 33419314 PMCID: PMC7766584 DOI: 10.3390/nano10122562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 11/22/2022]
Abstract
The formation of gallium nitride (GaN) semi-polar and non-polar nanostructures is of importance for improving light extraction/absorption of optoelectronic devices, creating optical resonant cavities or reducing the defect density. However, very limited studies of nanotexturing via dry etching have been performed, in comparison to wet etching. In this paper, we investigate the formation and morphology of semi-polar (112¯2) and non-polar (112¯0) GaN nanorods using inductively coupled plasma (ICP) etching. The impact of gas chemistry, pressure, temperature, radio-frequency (RF) and ICP power and time are explored. A dominant chemical component is found to have a significant impact on the morphology, being impacted by the polarity of the planes. In contrast, increasing the physical component enables the impact of crystal orientation to be minimized to achieve a circular nanorod profile with inclined sidewalls. These conditions were obtained for a small percentage of chlorine (Cl2) within the Cl2 + argon (Ar) plasma combined with a low pressure. Damage to the crystal was reduced by lowering the direct current (DC) bias through a reduction of the RF power and an increase of the ICP power.
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Affiliation(s)
- Pierre-Marie Coulon
- Department of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, UK;
| | - Peng Feng
- Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 4DE, UK; (P.F.); (T.W.)
| | - Tao Wang
- Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 4DE, UK; (P.F.); (T.W.)
| | - Philip A. Shields
- Department of Electrical & Electronic Engineering, University of Bath, Bath BA2 7AY, UK;
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16
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Gómez VJ, Graczyk M, Jam RJ, Lehmann S, Maximov I. Wafer-scale nanofabrication of sub-100 nm arrays by deep-UV displacement Talbot lithography. NANOTECHNOLOGY 2020; 31:295301. [PMID: 32259808 DOI: 10.1088/1361-6528/ab8764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this manuscript, we demonstrate the potential of replacing the standard bottom anti-reflective coating (BARC) with a polymethylglutarimide (PMGI) layer for wafer-scale nanofabrication by means of deep-UV displacement talbot lithography (DTL). PMGI is functioning as a developable non-UV sensitive bottom anti-reflective coating (DBARC). After introducing the fabrication process using a standard BARC-based coating and the novel PMGI-based one, the DTL nanopatterning capabilities for both coatings are compared by means of the fabrication of etched nanoholes in a dielectric layer and metal nanodots made by lift-off. Improvement of DTL capabilities are attributed to a reduction of process complexity by avoiding the use of O2 plasma etching of the BARC layer. We show the capacity of this approach to produce nanoholes or nanodots with diameters ranging from 95 to 200 nm at a wafer-scale using only one mask and a proper exposing dose. The minimum diameter of the nanoholes is reduced from 118 to 95 nm when using the PMGI-based coating instead of the BARC-based one. The possibilities opened by the PMGI-based coating are illustrated by the successful fabrication of an array of nanoholes with sub-100 nm diameter for GaAs nanowire growth on a 2″ GaAs wafer, a 2″ nanoimprint lithography (NIL) master stamp, and an array of Au nanodots made by lift-off on a 4″ silica wafer. Therefore, DTL possess the potential for wafer-scale manufacturing of nano-engineered materials.
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Affiliation(s)
- Víctor J Gómez
- Division of Solid State Physics and NanoLund, Lund University, Box 118, SE - 211 00, Lund, Sweden
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17
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Coulon PM, Feng P, Damilano B, Vézian S, Wang T, Shields PA. Influence of the reactor environment on the selective area thermal etching of GaN nanohole arrays. Sci Rep 2020; 10:5642. [PMID: 32221397 PMCID: PMC7101372 DOI: 10.1038/s41598-020-62539-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 03/12/2020] [Indexed: 12/01/2022] Open
Abstract
Selective area thermal etching (SATE) of gallium nitride is a simple subtractive process for creating novel device architectures and improving the structural and optical quality of III-nitride-based devices. In contrast to plasma etching, it allows, for example, the creation of enclosed features with extremely high aspect ratios without introducing ion-related etch damage. We report how SATE can create uniform and organized GaN nanohole arrays from c-plane and (11-22) semi-polar GaN in a conventional MOVPE reactor. The morphology, etching anisotropy and etch depth of the nanoholes were investigated by scanning electron microscopy for a broad range of etching parameters, including the temperature, the pressure, the NH3 flow rate and the carrier gas mixture. The supply of NH3 during SATE plays a crucial role in obtaining a highly anisotropic thermal etching process with the formation of hexagonal non-polar-faceted nanoholes. Changing other parameters affects the formation, or not, of non-polar sidewalls, the uniformity of the nanohole diameter, and the etch rate, which reaches 6 µm per hour. Finally, the paper discusses the SATE mechanism within a MOVPE environment, which can be applied to other mask configurations, such as dots, rings or lines, along with other crystallographic orientations.
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Affiliation(s)
- Pierre-Marie Coulon
- Department Electrical & Electronic Engineering, University of Bath, Bath, BA2 7AY, UK.
| | - Peng Feng
- Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S1 4DE, UK
| | - Benjamin Damilano
- Université Côte d'Azur, CNRS, CRHEA, rue B. Gregory, 06560, Valbonne, France
| | - Stéphane Vézian
- Université Côte d'Azur, CNRS, CRHEA, rue B. Gregory, 06560, Valbonne, France
| | - Tao Wang
- Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield, S1 4DE, UK
| | - Philip A Shields
- Department Electrical & Electronic Engineering, University of Bath, Bath, BA2 7AY, UK
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