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Surdo S, Barillaro G. Voltage- and Metal-assisted Chemical Etching of Micro and Nano Structures in Silicon: A Comprehensive Review. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2400499. [PMID: 38644330 DOI: 10.1002/smll.202400499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/12/2024] [Indexed: 04/23/2024]
Abstract
Sculpting silicon at the micro and nano scales has been game-changing to mold bulk silicon properties and expand, in turn, applications of silicon beyond electronics, namely, in photonics, sensing, medicine, and mechanics, to cite a few. Voltage- and metal-assisted chemical etching (ECE and MaCE, respectively) of silicon in acidic electrolytes have emerged over other micro and nanostructuring technologies thanks to their unique etching features. ECE and MaCE have enabled the fabrication of novel structures and devices not achievable otherwise, complementing those feasible with the deep reactive ion etching (DRIE) technology, the gold standard in silicon machining. Here, a comprehensive review of ECE and MaCE for silicon micro and nano machining is provided. The chemistry and physics ruling the dissolution of silicon are dissected and similarities and differences between ECE and MaCE are discussed showing that they are the two sides of the same coin. The processes governing the anisotropic etching of designed silicon micro and nanostructures are analyzed, and the modulation of etching profile over depth is discussed. The preparation of micro- and nanostructures with tailored optical, mechanical, and thermo(electrical) properties is then addressed, and their applications in photonics, (bio)sensing, (nano)medicine, and micromechanical systems are surveyed. Eventually, ECE and MaCE are benchmarked against DRIE, and future perspectives are highlighted.
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Affiliation(s)
- Salvatore Surdo
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, via G. Caruso 16, Pisa, 56122, Italy
| | - Giuseppe Barillaro
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, via G. Caruso 16, Pisa, 56122, Italy
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2
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Chang L, Liu X, Luo J, Lee CY, Zhang J, Fan X, Zhang W. Physiochemical Coupled Dynamic Nanosphere Lithography Enabling Multiple Metastructures from Single Mask. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2310469. [PMID: 38193751 DOI: 10.1002/adma.202310469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/14/2023] [Indexed: 01/10/2024]
Abstract
Metastructures are widely used in photonic devices, energy conversion, and biomedical applications. However, to fabricate multiple patterns continuously in single etching protocol with highly tunable photonic properties is challenging. Here, a simple and robust dynamic nanosphere lithography is proposed by inserting a spacer between the nanosphere assembly and the wafer. The nanosphere diameter decrease and uneven penetration of the spacer during etching lead to a dynamic masking process. Coupled anisotropic physical ion sputtering and ricocheting with isotropic chemical radical etching achieve highly tunable structures with various 3D patterns continuously forming through a single etching process. Specifically, the nanosphere diameters define the periodicity, the etched spacer forms the upper parts, and the wafer forms the lower parts. Each part of the structure is highly tunable through changing nanosphere diameter, spacer thickness, and etch conditions. Using this protocol, numerous structures of varying sizes including nanomushrooms, nanocones, nanopencils, and nanoneedles with diverse shapes are realized as proof of concepts. The broadband antireflection ability of the nanostructures and their use in surface-enhanced Raman spectroscopy are also demonstrated for practical application. This method substantially simplifies the fabrication procedure of various metastructures, paving the way for its application in multiple disciplines especially in photonic devices.
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Affiliation(s)
- Lin Chang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaohong Liu
- National University of Singapore (Chongqing) Research Institute, Chongqing, 401123, China
| | - Jie Luo
- College of Advanced Interdisciplinary Studies & Hunan Provincial, Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha, 410073, China
| | - Chong-Yew Lee
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, Penang, 11800, Malaysia
| | - Jianfa Zhang
- College of Advanced Interdisciplinary Studies & Hunan Provincial, Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha, 410073, China
| | - Xing Fan
- College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China
| | - Wei Zhang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
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Jang YJ, Sharma A, Jung JP. Advanced 3D Through-Si-Via and Solder Bumping Technology: A Review. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7652. [PMID: 38138794 PMCID: PMC10744783 DOI: 10.3390/ma16247652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/03/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023]
Abstract
Three-dimensional (3D) packaging using through-Si-via (TSV) is a key technique for achieving high-density integration, high-speed connectivity, and for downsizing of electronic devices. This paper describes recent developments in TSV fabrication and bonding methods in advanced 3D electronic packaging. In particular, the authors have overviewed the recent progress in the fabrication of TSV, various etching and functional layers, and conductive filling of TSVs, as well as bonding materials such as low-temperature nano-modified solders, transient liquid phase (TLP) bonding, Cu pillars, composite hybrids, and bump-free bonding, as well as the role of emerging high entropy alloy (HEA) solders in 3D microelectronic packaging. This paper serves as a guideline enumerating the current developments in 3D packaging that allow Si semiconductors to deliver improved performance and power efficiency.
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Affiliation(s)
- Ye Jin Jang
- Department of Materials Science and Engineering, University of Seoul, Seoul 02504, Republic of Korea;
| | - Ashutosh Sharma
- Department of Materials Science and Engineering, Ajou University, 206-Worldcup-ro, Yeongtong-gu, Gyeonggi-do, Suwon 16499, Republic of Korea
| | - Jae Pil Jung
- Department of Materials Science and Engineering, University of Seoul, Seoul 02504, Republic of Korea;
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Chen WS, Lee YC. Bi-Layer nanoimprinting lithography for metal-assisted chemical etching with application on silicon mold replication. NANOTECHNOLOGY 2023; 34:505301. [PMID: 37703872 DOI: 10.1088/1361-6528/acf93c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/12/2023] [Indexed: 09/15/2023]
Abstract
This paper reports a new type of nanoimprinting method called Bi-layer nanoimprinting lithography (BL-NIL), which can work along with metal-assisted chemical etching (MaCE) for fabricating nanostructures on silicon. In contrast to conventional nanoimprinting techniques, BL-NIL adds an interposing layer between the imprinting resist layer and silicon substrate. After the standard imprinting process, dry etching was used to etch away the residual imprinting layer and part of the interposing layer. Finally, the remaining interposing layer was wet-etched using its remover. This innovative approach can ensure cleanliness at the metal/silicon interface after metal lift-off processes, and therefore guarantees the success of MaCE. By combining BL-NIL and MaCE, expensive silicon molds with sub-micrometer/nanometer-scale feature sizes can be easily replicated and preserved. This is important for the application of nanoimprinting technologies in industrial manufacturing.
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Affiliation(s)
- Wei-Shen Chen
- Department of Mechanical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
| | - Yung-Chun Lee
- Department of Mechanical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
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Farhadi A, Bartschmid T, Bourret GR. Dewetting-Assisted Patterning: A Lithography-Free Route to Synthesize Black and Colored Silicon. ACS APPLIED MATERIALS & INTERFACES 2023; 15:44087-44096. [PMID: 37669230 PMCID: PMC10520913 DOI: 10.1021/acsami.3c08533] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/25/2023] [Indexed: 09/07/2023]
Abstract
We report the use of thermal dewetting to structure gold-based catalytic etching masks for metal-assisted chemical etching (MACE). The approach involves low-temperature dewetting of metal films to generate metal holey meshes with tunable morphologies. Combined with MACE, dewetting-assisted patterning is a simple, benchtop route to synthesize Si nanotubes, Si nanowalls, and Si nanowires with defined dimensions and optical properties. The approach is compatible with the synthesis of both black and colored nanostructured silicon substrates. In particular, we report the lithography-free fabrication of silicon nanowires with diameters down to 40 nm that support leaky wave-guiding modes, giving rise to vibrant colors. Additionally, micrometer-sized areas with tunable film composition and thickness were patterned via shadow masking. After dewetting and MACE, such patterned metal films produced regions with distinct nanostructured silicon morphologies and colors. To-date, the fabrication of colored silicon has relied on complicated nanoscale patterning processes. Dewetting-assisted patterning provides a simpler alternative that eliminates this requirement. Finally, the simple transfer of resonant SiNWs into ethanolic solutions with well-defined light absorption properties is reported. Such solution-dispersible SiNWs could open new avenues for the fabrication of ultrathin optoelectronic devices with enhanced and tunable light absorption.
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Affiliation(s)
- Amin Farhadi
- Department of Chemistry and
Physics of Materials, University of Salzburg, Jakob Haringerstraße 2a, A-5020 Salzburg, Austria
| | - Theresa Bartschmid
- Department of Chemistry and
Physics of Materials, University of Salzburg, Jakob Haringerstraße 2a, A-5020 Salzburg, Austria
| | - Gilles R. Bourret
- Department of Chemistry and
Physics of Materials, University of Salzburg, Jakob Haringerstraße 2a, A-5020 Salzburg, Austria
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Zheng Y, Zhao H, Cai Y, Jurado-Sánchez B, Dong R. Recent Advances in One-Dimensional Micro/Nanomotors: Fabrication, Propulsion and Application. NANO-MICRO LETTERS 2022; 15:20. [PMID: 36580129 PMCID: PMC9800686 DOI: 10.1007/s40820-022-00988-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/22/2022] [Indexed: 05/14/2023]
Abstract
Due to their tiny size, autonomous motion and functionalize modifications, micro/nanomotors have shown great potential for environmental remediation, biomedicine and micro/nano-engineering. One-dimensional (1D) micro/nanomotors combine the characteristics of anisotropy and large aspect ratio of 1D materials with the advantages of functionalization and autonomous motion of micro/nanomotors for revolutionary applications. In this review, we discuss current research progress on 1D micro/nanomotors, including the fabrication methods, driving mechanisms, and recent advances in environmental remediation and biomedical applications, as well as discuss current challenges and possible solutions. With continuous attention and innovation, the advancement of 1D micro/nanomotors will pave the way for the continued development of the micro/nanomotor field.
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Affiliation(s)
- Yuhong Zheng
- School of Chemistry, South China Normal University, Guangzhou, 510006, People's Republic of China
| | - He Zhao
- School of Chemistry, South China Normal University, Guangzhou, 510006, People's Republic of China
| | - Yuepeng Cai
- School of Chemistry, South China Normal University, Guangzhou, 510006, People's Republic of China.
| | - Beatriz Jurado-Sánchez
- Department of Analytical Chemistry, Physical Chemistry, and Chemical Engineering, Universidad de Alcala, 28871, Alcalá de Henares, Madrid, Spain.
- Chemical Research Institute "Andrés M. del Río", University of Alcala, 28871, Alcalá de Henares, Madrid, Spain.
| | - Renfeng Dong
- School of Chemistry, South China Normal University, Guangzhou, 510006, People's Republic of China.
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Zhang X, Liu Y, Yao C, Niu J, Li H, Xie C. Facile and stable fabrication of wafer-scale, ultra-black c-silicon with 3D nano/micro hybrid structures for solar cells. NANOSCALE ADVANCES 2022; 5:142-152. [PMID: 36605802 PMCID: PMC9765470 DOI: 10.1039/d2na00637e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 11/02/2022] [Indexed: 06/17/2023]
Abstract
Three-dimensional (3D) silicon (Si) nanostructures have attracted much attention in solar cells due to their excellent broadband and omnidirectional light-harvesting properties. However, the development of 3D Si nanostructures is still plagued by the trade-off between structural complexity and fabrication difficulty. Herein, we proposed a facile and stable approach toward the fabrication of wafer-scale, ultra-black crystalline silicon (c-Si) with nano/micro hybrid structures. The distinguishing advantage of this approach is that it allows the formation of 3D Si nano/micro hybrid structures in a single-round process, avoiding the need for multiple iterations of lithography, coating, and etching required in conventional processes. The nano/micro hybrid structure arrays we fabricated show a low reflectance of <1% in the 600-1000 nm wavelength range and absorb 98.82% of incident light in the visible and near-infrared regions from 400 to 1100 nm under AM 1.5 G illumination. Solar cells made from nano/micro hybrid 3D structure arrays have an efficiency improvement of about 11.4% compared to those made from mono-micropillar arrays, and they have potential applications in high-performance photovoltaic devices.
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Affiliation(s)
- Xiaomeng Zhang
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
- University of Chinese Academy of Sciences Beijing 100049 People's Republic of China
| | - Yu Liu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
| | - Chuhao Yao
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
- University of Chinese Academy of Sciences Beijing 100049 People's Republic of China
| | - Jiebin Niu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
| | - Hailiang Li
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
| | - Changqing Xie
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences Beijing 100029 People's Republic of China +86-010-82995581
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8
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Liu S, Wang J, Shao J, Ouyang D, Zhang W, Liu S, Li Y, Zhai T. Nanopatterning Technologies of 2D Materials for Integrated Electronic and Optoelectronic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200734. [PMID: 35501143 DOI: 10.1002/adma.202200734] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/12/2022] [Indexed: 06/14/2023]
Abstract
With the reduction of feature size and increase of integration density, traditional 3D semiconductors are unable to meet the future requirements of chip integration. The current semiconductor fabrication technologies are approaching their physical limits based on Moore's law. 2D materials such as graphene, transitional metal dichalcogenides, etc., are of great promise for future memory, logic, and photonic devices due to their unique and excellent properties. To prompt 2D materials and devices from the laboratory research stage to the industrial integrated circuit-level, it is necessary to develop advanced nanopatterning methods to obtain high-quality, wafer-scale, and patterned 2D products. Herein, the recent development of nanopatterning technologies, particularly toward realizing large-scale practical application of 2D materials is reviewed. Based on the technological progress, the unique requirement and advances of the 2D integration process for logic, memory, and optoelectronic devices are further summarized. Finally, the opportunities and challenges of nanopatterning technologies of 2D materials for future integrated chip devices are prospected.
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Affiliation(s)
- Shenghong Liu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Jing Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Jiefan Shao
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Decai Ouyang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Wenjing Zhang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Shiyuan Liu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yuan Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
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Lidsky D, Cain JM, Hutchins-Delgado T, Lu TM. Inverse metal-assisted chemical etching of germanium with gold and hydrogen peroxide. NANOTECHNOLOGY 2022; 34:065302. [PMID: 35835063 DOI: 10.1088/1361-6528/ac810c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Metal-assisted chemical etching (MACE) is a flexible technique for texturing the surface of semiconductors. In this work, we study the spatial variation of the etch profile, the effect of angular orientation relative to the crystallographic planes, and the effect of doping type. We employ gold in direct contact with germanium as the metal catalyst, and dilute hydrogen peroxide solution as the chemical etchant. With this catalyst-etchant combination, we observe inverse-MACE, where the area directly under gold is not etched, but the neighboring, exposed germanium experiences enhanced etching. This enhancement in etching decays exponentially with the lateral distance from the gold structure. An empirical formula for the gold-enhanced etching depth as a function of lateral distance from the edge of the gold film is extracted from the experimentally measured etch profiles. The lateral range of enhanced etching is approximately 10-20μm and is independent of etchant concentration. At length scales beyond a few microns, the etching enhancement is independent of the orientation with respect to the germanium crystallographic planes. The etch rate as a function of etchant concentration follows a power law with exponent smaller than 1. The observed etch rates and profiles are independent of whether the germanium substrate is n-type, p-type, or nearly intrinsic.
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Affiliation(s)
- D Lidsky
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - J M Cain
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - T Hutchins-Delgado
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
| | - T M Lu
- Sandia National Laboratories, Albuquerque, NM 87185, United States of America
- Center for Integrated Nanotechnologies, Sandia National Laboratories, Albuquerque, NM 87123, United States of America
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Li S, Chen K, Vähänissi V, Radevici I, Savin H, Oksanen J. Electron Injection in Metal Assisted Chemical Etching as a Fundamental Mechanism for Electroless Electricity Generation. J Phys Chem Lett 2022; 13:5648-5653. [PMID: 35708355 PMCID: PMC9234978 DOI: 10.1021/acs.jpclett.2c01302] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
Metal-assisted chemical etching (MACE) is a widely applied process for fabricating Si nanostructures. As an electroless process, it does not require a counter electrode, and it is usually considered that only holes in the Si valence band contribute to the process. In this work, a charge carrier collecting p-n junction structure coated with silver nanoparticles is used to demonstrate that also electrons in the conduction band play a fundamental role in MACE, and enable an electroless chemical energy conversion process that was not previously reported. The studied structures generate electricity at a power density of 0.43 mW/cm2 during MACE. This necessitates reformulating the microscopic electrochemical description of the Si-metal-oxidant nanosystems to separately account for electron and hole injections into the conduction and valence band of Si. Our work provides new insight into the fundamentals of MACE and demonstrates a radically new route to chemical energy conversion by solar cell-inspired devices.
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Affiliation(s)
- Shengyang Li
- Engineered
Nanosystems Group, School of Science, Aalto
University, Tietotie 1, Espoo, 02150, Finland
| | - Kexun Chen
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo, 02150, Finland
| | - Ville Vähänissi
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo, 02150, Finland
| | - Ivan Radevici
- Engineered
Nanosystems Group, School of Science, Aalto
University, Tietotie 1, Espoo, 02150, Finland
| | - Hele Savin
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo, 02150, Finland
| | - Jani Oksanen
- Engineered
Nanosystems Group, School of Science, Aalto
University, Tietotie 1, Espoo, 02150, Finland
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Song C, Ye B, Xu J, Chen J, Shi W, Yu C, An C, Zhu J, Zhang W. Large-Area Nanosphere Self-Assembly Monolayers for Periodic Surface Nanostructures with Ultrasensitive and Spatially Uniform SERS Sensing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2104202. [PMID: 34877766 DOI: 10.1002/smll.202104202] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/29/2021] [Indexed: 06/13/2023]
Abstract
Colloidal lithography provides a rapid and low-cost approach to construct 2D periodic surface nanostructures. However, an impressive demonstration to prepare large-area colloidal template is still missing. Here, a high-efficient and flexible technique is proposed to fabricate self-assembly monolayers consisting of orderly-packed polystyrene spheres at air/water interface via ultrasonic spray. This "non-contact" technique exhibits great advantages in terms of scalability and adaptability due to its renitent interface dynamic balance. More importantly, this technique is not only competent for self-assembly of single-sized polystyrene spheres, but also for binary polystyrene spheres, completely reversing the current hard situation of preparing large-area self-assembly monolayers. As a representative application, hexagonal-packed silver-coated silicon nanorods array (Si-NRs@Ag) is developed as an ultrasensitive surface-enhanced Raman scattering (SERS) substrate with very low limit-of-detection for selective detection of explosive 2,4,6-trinitrotoluene down to femtomolar (10-14 m) range. The periodicity and orderliness of the array allow hot spots to be designed and constructed in a homogeneous fashion, resulting in an incomparable uniformity and reproducibility of Raman signals. All these excellent properties come from the Si-NRs@Ag substrate based on the ordered structure, open surface, and wide-range electric field, providing a robust, consistent, and tunable platform for molecule trapping and SERS sensing for a wide range of organic molecules.
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Affiliation(s)
- Changkun Song
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Baoyun Ye
- School of Environment and Safety Engineering, North University of China, Xueyuan road 3, Taiyuan, 030051, P. R. China
| | - Jianyong Xu
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Junhong Chen
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Wei Shi
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Chunpei Yu
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Chongwei An
- School of Environment and Safety Engineering, North University of China, Xueyuan road 3, Taiyuan, 030051, P. R. China
| | - Junwu Zhu
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
| | - Wenchao Zhang
- Micro-Nano Energetic Devices Key Laboratory, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Xiaolingwei street 200, Nanjing, 210094, P. R. China
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12
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Lan J, Liu J, Hu S, Yang Y. Highly efficient light trapping of clustered silicon nanowires for solar cell applications. APPLIED OPTICS 2022; 61:369-374. [PMID: 35200871 DOI: 10.1364/ao.446163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Due to their excellent photoelectric performance, nanostructures have attracted considerable attention in research to improve the power conversion efficiency of thin-film solar cells (TFSCs). Furthermore, cylindrical silicon nanowires (Cy-SiNWs) are regarded as promising candidates for a new generation of TFSCs. On this basis, many new nanostructures derived from conventional Cy-SiNWs have been studied extensively, but most of these structures require high manufacturing accuracy because of their complex morphology. In this paper, an ingenious design of clustered silicon nanowires (Cl-SiNWs) is introduced, whose cross section is similar to the flower shape and consists of four arcs with the same radius. Hence, it requires lower manufacturing difficulty compared with nanostructures with curvature variation of the cross-section profile (i.e., elliptic shape, crescent shape, etc.). In this study, the optical and electrical characterizations are numerically investigated using the finite-difference time-domain method. The numerical simulation shows that the optimized Cl-SiNWs achieve an optical ultimate efficiency (ηul) and circuit current density (Jsc) of 33.66% and 27.54mA/cm2, respectively, with an enhancement of 7.3% over conventional Cy-SiNWs. Further, the ηul and Jsc improve to 42.20% and 34.53mA/cm2 by adding the silicon substrate and silver backreflector. More importantly, the ηul of Cl-SiNWs always obtained a higher value than Cy-SiNWs at a recommended diameter range of 360-560 nm. Therefore, the suggested Cl-SiNWs have exhibited tremendous potential for the future development of low-cost and highly efficient solar cells.
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Kolasinski KW. Metal-Assisted Catalytic Etching (MACE) for Nanofabrication of Semiconductor Powders. MICROMACHINES 2021; 12:776. [PMID: 34209231 PMCID: PMC8304928 DOI: 10.3390/mi12070776] [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: 06/12/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 12/31/2022]
Abstract
Electroless etching of semiconductors has been elevated to an advanced micromachining process by the addition of a structured metal catalyst. Patterning of the catalyst by lithographic techniques facilitated the patterning of crystalline and polycrystalline wafer substrates. Galvanic deposition of metals on semiconductors has a natural tendency to produce nanoparticles rather than flat uniform films. This characteristic makes possible the etching of wafers and particles with arbitrary shape and size. While it has been widely recognized that spontaneous deposition of metal nanoparticles can be used in connection with etching to porosify wafers, it is also possible to produced nanostructured powders. Metal-assisted catalytic etching (MACE) can be controlled to produce (1) etch track pores with shapes and sizes closely related to the shape and size of the metal nanoparticle, (2) hierarchically porosified substrates exhibiting combinations of large etch track pores and mesopores, and (3) nanowires with either solid or mesoporous cores. This review discussed the mechanisms of porosification, processing advances, and the properties of the etch product with special emphasis on the etching of silicon powders.
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Affiliation(s)
- Kurt W Kolasinski
- Department of Chemistry, West Chester University, West Chester, PA 19383, USA
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