1
|
Jeong HW, Ajay A, Döblinger M, Sturm S, Gómez Ruiz M, Zell R, Mukhundhan N, Stelzner D, Lähnemann J, Müller-Caspary K, Finley JJ, Koblmüller G. Axial Growth Characteristics of Optically Active InGaAs Nanowire Heterostructures for Integrated Nanophotonic Devices. ACS APPLIED NANO MATERIALS 2024; 7:3032-3041. [PMID: 38357219 PMCID: PMC10863613 DOI: 10.1021/acsanm.3c05392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 02/16/2024]
Abstract
III-V semiconductor nanowire (NW) heterostructures with axial InGaAs active regions hold large potential for diverse on-chip device applications, including site-selectively integrated quantum light sources, NW lasers with high material gain, as well as resonant tunneling diodes and avalanche photodiodes. Despite various promising efforts toward high-quality single or multiple axial InGaAs heterostacks using noncatalytic growth mechanisms, the important roles of facet-dependent shape evolution, crystal defects, and the applicability to more universal growth schemes have remained elusive. Here, we report the growth of optically active InGaAs axial NW heterostructures via completely catalyst-free, selective-area molecular beam epitaxy directly on silicon (Si) using GaAs(Sb) NW arrays as tunable, high-uniformity growth templates and highlight fundamental relationships between structural, morphological, and optical properties of the InGaAs region. Structural, compositional, and 3D-tomographic characterizations affirm the desired directional growth along the NW axis with no radial growth observed. Clearly distinct luminescence from the InGaAs active region is demonstrated, where tunable array-geometry parameters and In content up to 20% are further investigated. Based on the underlying twin-induced growth mode, we further describe the facet-dependent shape and interface evolution of the InGaAs segment and its direct correlation with emission energy.
Collapse
Affiliation(s)
- Hyowon W. Jeong
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| | - Akhil Ajay
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| | - Markus Döblinger
- Department
of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Sebastian Sturm
- Department
of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Mikel Gómez Ruiz
- Paul-Drude-Institute
for Solid State Electronics, Leibniz-Institut
Im Forschungsverbund Berlin e.V., 10117 Berlin, Germany
| | - Richard Zell
- Department
of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Nitin Mukhundhan
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| | - Daniel Stelzner
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| | - Jonas Lähnemann
- Paul-Drude-Institute
for Solid State Electronics, Leibniz-Institut
Im Forschungsverbund Berlin e.V., 10117 Berlin, Germany
| | - Knut Müller-Caspary
- Department
of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Jonathan J. Finley
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| | - Gregor Koblmüller
- Walter
Schottky Institute, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching bei München, Germany
| |
Collapse
|
2
|
Bougerol C, Robin E, Di Russo E, Bellet-Amalric E, Grenier V, Ajay A, Rigutti L, Monroy E. Solubility Limit of Ge Dopants in AlGaN: A Chemical and Microstructural Investigation Down to the Nanoscale. ACS APPLIED MATERIALS & INTERFACES 2021; 13:4165-4173. [PMID: 33449632 DOI: 10.1021/acsami.0c19174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Attaining low-resistivity AlxGa1-xN layers is one keystone to improve the efficiency of light-emitting devices in the ultraviolet spectral range. Here, we present a microstructural analysis of AlxGa1-xN/Ge samples with 0 ≤ x ≤ 1, and a nominal doping level in the range of 1020 cm-3, together with the measurement of Ge concentration and its spatial distribution down to the nanometer scale. AlxGa1-xN/Ge samples with x ≤ 0.2 do not present any sign of inhomogeneity. However, samples with x > 0.4 display μm-size Ge crystallites at the surface. Ge segregation is not restricted to the surface: Ge-rich regions with a size of tens of nanometers are observed inside the AlxGa1-xN/Ge layers, generally associated with Ga-rich regions around structural defects. With these local exceptions, the AlxGa1-xN/Ge matrix presents a homogeneous Ge composition which can be significantly lower than the nominal doping level. Precise measurements of Ge in the matrix provide a view of the solubility diagram of Ge in AlxGa1-xN as a function of the Al mole fraction. The solubility of Ge in AlN is extremely low. Between AlN and GaN, the solubility increases linearly with the Ga mole fraction in the ternary alloy, which suggests that the Ge incorporation takes place by substitution of Ga atoms only. The maximum percentage of Ga sites occupied by Ge saturates around 1%. The solubility issues and Ge segregation phenomena at different length scales likely play a role in the efficiency of Ge as an n-type AlGaN dopant, even at Al concentrations where Ge DX centers are not expected to manifest. Therefore, this information can have direct impact on the performance of Ge-doped AlGaN light-emitting diodes, particularly in the spectral range for disinfection (≈260 nm), which requires heavily doped alloys with a high Al mole fraction.
Collapse
Affiliation(s)
- Catherine Bougerol
- Univ. Grenoble-Alpes, Institut Néel-CNRS, 25 av. des Martyrs, 38000 Grenoble, France
| | - Eric Robin
- Univ. Grenoble-Alpes, CEA, IRIG, MEM, 17 av. des Martyrs, 38000 Grenoble, France
| | - Enrico Di Russo
- UNIROUEN, CNRS, Groupe de Physique des Matériaux, Normandie Université, 76000 Rouen, France
| | - Edith Bellet-Amalric
- Univ. Grenoble-Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 17 av. des Martyrs, 38000 Grenoble, France
| | - Vincent Grenier
- Univ. Grenoble-Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 17 av. des Martyrs, 38000 Grenoble, France
| | - Akhil Ajay
- Univ. Grenoble-Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 17 av. des Martyrs, 38000 Grenoble, France
| | - Lorenzo Rigutti
- UNIROUEN, CNRS, Groupe de Physique des Matériaux, Normandie Université, 76000 Rouen, France
| | - Eva Monroy
- Univ. Grenoble-Alpes, CEA, IRIG, 17 av. des Martyrs, 38000 Grenoble, France
| |
Collapse
|
3
|
Dimkou I, Harikumar A, Donatini F, Lähnemann J, den Hertog MI, Bougerol C, Bellet-Amalric E, Mollard N, Ajay A, Ledoux G, Purcell ST, Monroy E. Assessment of AlGaN/AlN superlattices on GaN nanowires as active region of electron-pumped ultraviolet sources. NANOTECHNOLOGY 2020; 31:204001. [PMID: 31986502 DOI: 10.1088/1361-6528/ab704d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this paper, we describe the design and characterization of 400 nm long (88 periods) Al x Ga1-x N/AlN (0 ≤ x ≤ 0.1) quantum dot superlattices deposited on self-assembled GaN nanowires for application in electron-pumped ultraviolet sources. The optical performance of GaN/AlN superlattices on nanowires is compared with the emission of planar GaN/AlN superlattices with the same periodicity and thickness grown on bulk GaN substrates along the N-polar and metal-polar crystallographic axes. The nanowire samples are less sensitive to nonradiative recombination than planar layers, attaining internal quantum efficiencies (IQE) in excess of 60% at room temperature even under low injection conditions. The IQE remains stable for higher excitation power densities, up to 50 kW cm-2. We demonstrate that the nanowire superlattice is long enough to collect the electron-hole pairs generated by an electron beam with an acceleration voltage V A = 5 kV. At such V A, the light emitted from the nanowire ensemble does not show any sign of quenching under constant electron beam excitation (tested for an excitation power density around 8 kW cm-2 over the scale of minutes). Varying the dot/barrier thickness ratio and the Al content in the dots, the nanowire peak emission can be tuned in the range from 340 to 258 nm.
Collapse
Affiliation(s)
- I Dimkou
- Univ. Grenoble-Alpes, CEA, LETI, F-38000 Grenoble, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Lin L, Huo J, Peng P, Zou G, Liu L, Duley WW, Zhou YN. Contact engineering of single core/shell SiC/SiO 2 nanowire memory unit with high current tolerance using focused femtosecond laser irradiation. NANOSCALE 2020; 12:5618-5626. [PMID: 32100779 DOI: 10.1039/c9nr10690a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Single nanowire memory units are of particular interest in the design of high-density nanoelectronic circuits, but the performance due to weak contact state remains a major problem. In this paper, bonding between core/shell SiC/SiO2 nanowire and Au electrodes can be improved via local contact engineering with femtosecond (fs) laser irradiation. An optimized heterojunction (Au-SiO2-SiC) is possible since plasmonic enhanced optical absorption can be localized at the metal-oxide (Au-SiO2) interface. Electron transport across the barrier and charge accumulation at the oxide-semiconductor (SiO2-SiC) interface are improved in nanowire circuits. A fast and stable resistance change can be achieved after only one biasing cycle ('write') and the written state can be read/extracted at a low voltage (∼ 0.5 V). Unlike other as-built nanowire circuits, the resistance state can be retained for 10 min in the absence of external power, indicating that these devices can be used for short-term memory units. High current tolerance is also provided in the circuit by the surface oxide shell which acts to protect the inner SiC core. The current density carried by the single SiC/SiO2 nanowire circuit can be as high as ∼3 × 106 A cm-2 before break down, and that breakdown occurs as a two-stage process.
Collapse
Affiliation(s)
- Luchan Lin
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P.R. China. and Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Jinpeng Huo
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P.R. China.
| | - Peng Peng
- School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, P.R. China
| | - Guisheng Zou
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P.R. China.
| | - Lei Liu
- Department of Mechanical Engineering, Tsinghua University, Beijing 100084, P.R. China.
| | - Walt W Duley
- Department of Physics and Astronomy, University of Waterloo, Waterloo N2L 3G1, Canada
| | - Y Norman Zhou
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo N2L 3G1, Canada
| |
Collapse
|
5
|
Barrigón E, Heurlin M, Bi Z, Monemar B, Samuelson L. Synthesis and Applications of III-V Nanowires. Chem Rev 2019; 119:9170-9220. [PMID: 31385696 DOI: 10.1021/acs.chemrev.9b00075] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Low-dimensional semiconductor materials structures, where nanowires are needle-like one-dimensional examples, have developed into one of the most intensely studied fields of science and technology. The subarea described in this review is compound semiconductor nanowires, with the materials covered limited to III-V materials (like GaAs, InAs, GaP, InP,...) and III-nitride materials (GaN, InGaN, AlGaN,...). We review the way in which several innovative synthesis methods constitute the basis for the realization of highly controlled nanowires, and we combine this perspective with one of how the different families of nanowires can contribute to applications. One reason for the very intense research in this field is motivated by what they can offer to main-stream semiconductors, by which ultrahigh performing electronic (e.g., transistors) and photonic (e.g., photovoltaics, photodetectors or LEDs) technologies can be merged with silicon and CMOS. Other important aspects, also covered in the review, deals with synthesis methods that can lead to dramatic reduction of cost of fabrication and opportunities for up-scaling to mass production methods.
Collapse
Affiliation(s)
- Enrique Barrigón
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Magnus Heurlin
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden.,Sol Voltaics AB , Scheelevägen 63 , 223 63 Lund , Sweden
| | - Zhaoxia Bi
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Bo Monemar
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| | - Lars Samuelson
- Division of Solid State Physics and NanoLund , Lund University , Box 118, 22100 Lund , Sweden
| |
Collapse
|
6
|
Lähnemann J, Browne DA, Ajay A, Jeannin M, Vasanelli A, Thomassin JL, Bellet-Amalric E, Monroy E. Near- and mid-infrared intersubband absorption in top-down GaN/AlN nano- and micro-pillars. NANOTECHNOLOGY 2019; 30:054002. [PMID: 30500783 DOI: 10.1088/1361-6528/aaef72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a systematic study of top-down processed GaN/AlN heterostructures for intersubband optoelectronic applications. Samples containing quantum well superlattices that display either near- or mid-infrared intersubband absorption were etched into nano- and micro-pillar arrays in an inductively coupled plasma. We investigate the influence of this process on the structure and strain-state, on the interband emission and on the intersubband absorption. Notably, for pillar spacings significantly smaller (≤1/3) than the intersubband wavelength, the magnitude of the intersubband absorption is not reduced even when 90% of the material is etched away and a similar linewidth is obtained. The same holds for the interband emission. In contrast, for pillar spacings on the order of the intersubband absorption wavelength, the intersubband absorption is masked by refraction effects and photonic crystal modes. The presented results are a first step towards micro- and nano-structured group-III nitride devices relying on intersubband transitions.
Collapse
Affiliation(s)
- Jonas Lähnemann
- Université Grenoble-Alpes, CEA, INAC, PHELIQS, 17 av. des Martyrs, F-38000, Grenoble, France. Paul-Drude-Institut für Festkörperelektronik, Leibniz Institut im Forschugnsverbund Berlin e.V., Hausvogteiplatz 5-7, D-10117, Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Gu H, Tian F, Zhang C, Xu K, Wang J, Chen Y, Deng X, Liu X. Recovery Performance of Ge-Doped Vertical GaN Schottky Barrier Diodes. NANOSCALE RESEARCH LETTERS 2019; 14:40. [PMID: 30706287 PMCID: PMC6355890 DOI: 10.1186/s11671-019-2872-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 01/20/2019] [Indexed: 05/31/2023]
Abstract
Vertical GaN Schottky barrier diodes (SBDs) were fabricated on Ge-doped free-standing GaN substrates. The crystal quality of the SBDs was characterized by cathode luminescence measurement, and the dislocation density was determined to be ~ 1.3 × 106 cm- 2. With the electrical performance measurements conducted, the SBDs show a low turn-on voltage Von (0.70~0.78 V) and high current Ion/Ioff ratio (9.9 × 107~1.3 × 1010). The reverse recovery characteristics were investigated. The reverse recovery time was obtained to be 15.8, 16.2, 18.1, 21.22, and 24.5 ns for the 100-, 200-, 300-, 400-, and 500-μm-diameter SBDs, respectively. Meanwhile, the reverse recovery time and reverse recovery charge both show a significant positive correlation with the electrode area.
Collapse
Affiliation(s)
- Hong Gu
- College of Materials Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Special Functional Materials, Chinese Engineering and Research Institute of Microelectronics, Shenzhen University, Shenzhen, 518060 People’s Republic of China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Feifei Tian
- Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou, 215123 People’s Republic of China
| | - Chunyu Zhang
- Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou, 215123 People’s Republic of China
| | - Ke Xu
- Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou, 215123 People’s Republic of China
| | - Jiale Wang
- College of Materials Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Special Functional Materials, Chinese Engineering and Research Institute of Microelectronics, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Yong Chen
- College of Materials Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Special Functional Materials, Chinese Engineering and Research Institute of Microelectronics, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Xuanhua Deng
- College of Materials Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Special Functional Materials, Chinese Engineering and Research Institute of Microelectronics, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| | - Xinke Liu
- College of Materials Science and Engineering, Guangdong Research Center for Interfacial Engineering of Functional Materials, Shenzhen Key Laboratory of Special Functional Materials, Chinese Engineering and Research Institute of Microelectronics, Shenzhen University, Shenzhen, 518060 People’s Republic of China
| |
Collapse
|
8
|
Ajay A, Blasco R, Polaczyński J, Spies M, Den Hertog MI, Monroy E. Intersubband absorption in GaN nanowire heterostructures at mid-infrared wavelengths. NANOTECHNOLOGY 2018; 29:385201. [PMID: 29947335 DOI: 10.1088/1361-6528/aacf55] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this paper, we study intersubband characteristics of GaN/AlN and GaN/Al0.4Ga0.6N heterostructures in GaN nanowires structurally designed to absorb in the mid-infrared wavelength region. Increasing the GaN well width from 1.5 to 5.7 nm leads to a red shift of the intersubband absorption from 1.4 to 3.4 μm. The red shift in larger quantum wells is amplified by the fact that one of the GaN/AlN heterointerfaces (corresponding to the growth of GaN on AlN) is not sharp but rather a graded alloy extending around 1.5-2 nm. Using AlGaN instead of AlN for the same barrier dimensions, we observe the effects of reduced polarization, which blue shifts the band-to-band transitions and red shifts the intersubband transitions. In heavily doped GaN/AlGaN nanowires, a broad absorption band is observed in the 4.5-6.4 μm spectral region.
Collapse
Affiliation(s)
- A Ajay
- Univ. Grenoble-Alpes, CEA-INAC-PHELIQS, 17 av. des Martyrs, F-38000 Grenoble, France
| | | | | | | | | | | |
Collapse
|
9
|
Lähnemann J, Ajay A, Den Hertog MI, Monroy E. Near-Infrared Intersubband Photodetection in GaN/AlN Nanowires. NANO LETTERS 2017; 17:6954-6960. [PMID: 28961016 DOI: 10.1021/acs.nanolett.7b03414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Intersubband optoelectronic devices rely on transitions between quantum-confined electron levels in semiconductor heterostructures, which enables infrared (IR) photodetection in the 1-30 μm wavelength window with picosecond response times. Incorporating nanowires as active media could enable an independent control over the electrical cross-section of the device and the optical absorption cross-section. Furthermore, the three-dimensional carrier confinement in nanowire heterostructures opens new possibilities to tune the carrier relaxation time. However, the generation of structural defects and the surface sensitivity of GaAs nanowires have so far hindered the fabrication of nanowire intersubband devices. Here, we report the first demonstration of intersubband photodetection in a nanowire, using GaN nanowires containing a GaN/AlN superlattice absorbing at 1.55 μm. The combination of spectral photocurrent measurements with 8-band k·p calculations of the electronic structure supports the interpretation of the result as intersubband photodetection in these extremely short-period superlattices. We observe a linear dependence of the photocurrent with the incident illumination power, which confirms the insensitivity of the intersubband process to surface states and highlights how architectures featuring large surface-to-volume ratios are suitable as intersubband photodetectors. Our analysis of the photocurrent characteristics points out routes for an improvement of the device performance. This first nanowire based intersubband photodetector represents a technological breakthrough that paves the way to a powerful device platform with potential for ultrafast, ultrasensitive photodetectors and highly efficient quantum cascade emitters with improved thermal stability.
Collapse
Affiliation(s)
- Jonas Lähnemann
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
| | - Akhil Ajay
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
| | - Martien I Den Hertog
- Université Grenoble-Alpes, CNRS, Institut Néel , 25 av. des Martyrs, 38000 Grenoble, France
| | - Eva Monroy
- Université Grenoble-Alpes, CEA, INAC, PHELIQS , 17 av. des Martyrs, 38000 Grenoble, France
| |
Collapse
|