Article
Optics
Yaying Liu, Zhaojun Liu, Kei may Lau
Summary: This study presents an all-GaN-based mu LED display with monolithic integrated HEMT and mu LED pixels using the selective area regrowth method. The optimized regrowth pattern improves the crystal quality of regrown mu LED, resulting in high light output power and peak EQE for the mu LED-HEMT. TMAH treatment and Al2O3 surface passivation are performed to minimize nonradiative recombination caused by dry etching damage. Images of HKUST are successfully shown on the customized mu LED-HEMT display board.
Article
Chemistry, Multidisciplinary
Jason Jung, Sander G. Schellingerhout, Markus F. Ritter, Sofieke C. ten Kate, Orson A. H. van der Molen, Sem de Loijer, Marcel A. Verheijen, Heike Riel, Fabrizio Nichele, Erik P. A. M. Bakkers
Summary: This study introduces a method for the growth of large-scale lead telluride networks using molecular beam epitaxy. Despite the lattice mismatch, different crystal structure, and diverging thermal expansion coefficient, the researchers were able to obtain high-quality single-crystalline nanowire networks. The resulting material exhibits high mobility and low-temperature phase coherence, indicating its high potential as a basis for topological networks.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Min-joo Ahn, Woo-seop Jeong, Kyu-yeon Shim, Seongho Kang, Hwayoung Kim, Dae-sik Kim, Junggeun Jhin, Jaekyun Kim, Dongjin Byun
Summary: This study provides experimental evidence on the mechanism of gallium nitride (GaN) selective-area growth (SAG) on a polished plateau-patterned sapphire substrate (PP-PSS) with aluminum nitride (AlN) buffer layers under the same deposition conditions. The SAG of GaN was found only on the plateau region of the PP-PSS, regardless of the number of growth cycles. The analysis shows that the AlN buffer layer in the plateau region has a higher surface energy and a crystal orientation indicated by AlN [001], while other regions exhibit lower crystallinity and surface energies. The direct analysis results of PP-PSS using transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) support the findings of the indirect samples. Therefore, the crystallinity, crystal orientation, and surface energy play a role in the GaN SAG of the deposited layer under the same conditions.
Article
Physics, Applied
Lian Zhang, Zhe Cheng, Yawei He, Jianxing Xu, Lifang Jia, Xinyuan Wang, Shiyong Zhang, Wei Tan, Yun Zhang
Summary: This study focuses on the electron concentration and mobility of SAG n(+)-GaN on InAlN/GaN HEMTs using MOCVD, revealing that the electron mobility of SAG GaN is significantly affected by thickness. A gas flow model is proposed to guide the regrowth for improving electron mobility. High mobility and low resistance are achieved in the SAG GaN, contributing to the performance of the HEMTs.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Aadil Waseem, Muhammad Ali Johar, Mostafa Afifi Hassan, Indrajit Bagal, Ameer Abdullah, Jun-Seok Ha, June Key Lee, Sang-Wan Ryu
Summary: The crystallographic orientation control of GaN nanowires was achieved by varying the indium composition in the Ga-Au alloy catalyst, with the alloy droplet size determining the density of the nanowires. Increasing the In composition inside the alloy catalyst shifted the crystallographic orientation of the GaN nanowires from m- to c-axis.
Article
Chemistry, Multidisciplinary
Nian Jiang, Saptarsi Ghosh, Martin Frentrup, Simon M. Fairclough, Kagiso Loeto, Gunnar Kusch, Rachel A. Oliver, Hannah J. Joyce
Summary: Understanding the growth mechanisms of III-nitride nanowires is crucial for harnessing their full potential. A systematic study explores the growth of silane-assisted GaN nanowires on c-sapphire substrates, investigating the surface evolution of the substrates during annealing, nitridation, and nucleation steps. Both Ga-polar and N-polar GaN nanowires were grown, with N-polar nanowires exhibiting faster growth. The presence of protuberance structures and ring-like features in N-polar GaN nanowires suggests energetically favorable nucleation sites at inversion domain boundaries, while the impact on device performance is confined to the protuberance structure area.
NANOSCALE ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Santhanu Panikar Ramanandan, Petar Tomic, Nicholas Paul Morgan, Andrea Giunto, Alok Rudra, Klaus Ensslin, Thomas Ihn, Anna Fontcuberta i Morral
Summary: We successfully obtained a germanium nanowire network by selectively growing on nanopatterned slits in a metalorganic vapor phase epitaxy system. Measurements on the nanowire devices showed high hole doping and short mean free path, while revealing quantum transport phenomena and spin-orbit length.
Article
Chemistry, Multidisciplinary
Pujitha Perla, H. Aruni Fonseka, Patrick Zellekens, Russell Deacon, Yisong Han, Jonas Koelzer, Timm Moerstedt, Benjamin Bennemann, Abbas Espiari, Koji Ishibashi, Detlev Gruetzmacher, Ana M. Sanchez, Mihail Ion Lepsa, Thomas Schaepers
Summary: Josephson junctions based on InAs semiconducting nanowires and Nb superconducting electrodes were fabricated in situ using a special shadow evaporation scheme. The junctions exhibit a clean InAs/Nb interface and a high junction transparency, with a clear Josephson supercurrent that can be controlled by a bottom gate. This in situ prepared Nb/InAs nanowire contacts show potential for use in superconducting quantum circuits requiring large magnetic fields.
NANOSCALE ADVANCES
(2021)
Article
Chemistry, Multidisciplinary
Vladislav O. Gridchin, Liliia N. Dvoretckaia, Konstantin P. Kotlyar, Rodion R. Reznik, Alesya Parfeneva, Anna S. Dragunova, Natalia Kryzhanovskaya, Vladimir G. Dubrovskii, George E. Cirlin
Summary: GaN nanowires were successfully grown using selective area epitaxy technique on SiOx/Si substrate, and a temperature-flux ratio map was established to control the growth selectivity. High crystal quality in the GaN nanowires was confirmed through low-temperature photoluminescence measurements.
Article
Chemistry, Physical
Sonachand Adhikari, Felipe Kremer, Mykhaylo Lysevych, Chennupati Jagadish, Hark Hoe Tan
Summary: GaN/AlGaN core-shell nanowires with various Al compositions have been grown on GaN nanowire array. The AlGaN shells have lower Al compositions than the gas phase input ratio. Defect-related luminescence has been observed in the AlGaN shells, with partial dislocations as the dominant defects. Growth of nonpolar m-plane AlxGa1-xN/AlyGa1-yN quantum wells on the sidewalls of the GaN nanowires shows excellent morphology and optical emission.
NANOSCALE HORIZONS
(2023)
Article
Chemistry, Multidisciplinary
Mohadeseh A. Baboli, Alireza Abrand, Robert A. Burke, Anastasiia Fedorenko, Thomas S. Wilhelm, Stephen J. Polly, Madan Dubey, Seth M. Hubbard, Parsian K. Mohseni
Summary: This study demonstrates the selective-area van der Waals epitaxy of InAs nanowires on isolated molybdenum disulfide (MoS2) domains. By exploring MOCVD growth parameters, single nanowires are positioned on multi-layer MoS2 micro-plates with pattern-free growth. Pre-growth poly-l-lysine surface treatment is essential for mitigating nucleation along MoS2 edges and promoting growth along the interior region. The resulting crystal structure is a combination of wurtzite and zinc-blend phases with a common lattice arrangement between InAs nanowires and MoS2 domains.
NANOSCALE ADVANCES
(2021)
Article
Materials Science, Ceramics
Wei Chen, Teng Jiao, Zhaoti Diao, Zhengda Li, Peiran Chen, Xinming Dang, Xin Dong, Yuantao Zhang, Baolin Zhang
Summary: ss-Ga2O3 nanowire films were synthesized on Si(111) substrate by selective area growth (SAG) using metal-organic chemical vapor deposition (MOCVD). The effects of MOCVD process parameters on SAG were discussed by calculating Ga supersaturation. Transmission electron microscopy confirmed the preferential orientation of (002) crystal plane in ss-Ga2O3 nanowires. P-Si/ss-Ga2O3 nanowire heterojunctions were fabricated and exhibited high film resistance.
CERAMICS INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
A. Bucamp, C. Coinon, S. Lepilliet, D. Troadec, G. Patriarche, M. H. Diallo, V Avramovic, K. Haddadi, X. Wallart, L. Desplanque
Summary: In-plane InGaAs/Ga(As)Sb heterojunction tunnel diodes were fabricated using selective area molecular beam epitaxy. Both radial core/shell nanowires and axial heterojunction structures achieved negative differential resistances with large peak current densities.
Review
Physics, Applied
Romualdo Alejandro Ferreyra, Bingjun Li, Sizhen Wang, Jung Han
Summary: Selective area doping in GaN, especially p-type, is crucial for advanced device structures in high-power applications. This paper reviews recent advances in selective area etching and regrowth, ion implantation, and polarity-dependent doping, which may contribute to the practical realization of GaN-based power devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Syed M. N. Hasan, Weicheng You, Arnob Ghosh, Sharif Md. Sadaf, Shamsul Arafin
Summary: This work presents the selective area epitaxy of GaN nanostructures grown on Ga-polar GaN/sapphire substrates by plasma-assisted molecular beam epitaxy. Three types of nanostructures, namely nanowires, nanofins, and nanorings, are demonstrated on GaN-on-sapphire templates, with investigation on the control of their morphology and orientation. This study advances the understanding of selective area epitaxy for defining complex III-nitride nanostructures, which are important in the fields of nanotechnology and nanoscience.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Physics, Applied
Xinrong Zuo, Ziyuan Li, Wei Wen Wong, Yang Yu, Xi Li, Jun He, Lan Fu, Hark Hoe Tan, Chennupati Jagadish, Xiaoming Yuan
Summary: In this work, InAs nanosheet arrays were proposed and designed to achieve polarization-independent, angle-insensitive, and ultrawide infrared absorption. By optimizing the design, high absorption in a broad wavelength range from visible light to mid-wave infrared was achieved.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Wei Wen Wong, Chennupati Jagadish, Hark Hoe Tan
Summary: III-V WGM micro-cavity lasers are widely used in modern optoelectronic devices, with excellent optical performance. This review presents advances in fabrication techniques, emission outcoupling methods, and practical applications. Highly-scalable bottom-up methods have shown potential for fabricating low-loss WGM lasers. Various techniques have been developed to outcouple WGM emission into waveguides or direct it into free-space with small beam divergence. In addition to serving as integrated photonic components, III-V WGM micro-cavity lasers have demonstrated exciting potential in label-free sensing and cQED research.
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Nikita Gagrani, Kaushal Vora, Chennupati Jagadish, Hark Hoe Tan
Summary: This study investigates the characteristics and applications of p-type transparent conducting oxides (TCOs) through the deposition of SnxNiyOz films. The study explores the optical and electrical properties, band alignment, and stability of the films, as well as the behavior of LEDs using these materials. The results demonstrate the potential of SnxNiyOz as a high-performance p-type TCO for transparent electronics and optoelectronics applications.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Physical
Joshua Zheyan Soo, Bikesh Gupta, Asim Riaz, Chennupati Jagadish, Hark Hoe Tan, Siva Karuturi
Summary: To achieve low-cost and sustainable hydrogen production, developing facile approaches to fabricate water splitting (photo)electrodes based on earth-abundant catalysts is crucial. In this study, a substrate-agnostic method of depositing NiFe layered double hydroxide (LDH) catalyst on diverse substrates for water splitting (photo)anodes is demonstrated. The deposited catalyst electrodes exhibit consistent and sustained water splitting performance across various substrates, and possess regenerative capabilities.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Teja Potocnik, Peter J. Christopher, Ralf Mouthaan, Tom Albrow-Owen, Oliver J. Burton, Chennupati Jagadish, Hark Hoe Tan, Timothy D. Wilkinson, Stephan Hofmann, Hannah J. Joyce, Jack A. Alexander-Webber
Summary: We present a high-throughput method for identifying and characterizing individual nanowires, and for designing electrode patterns with high alignment accuracy. Our method utilizes an optimized marker system called LithoTag, which allows for nanometer-scale position determination of nanostructures. By incorporating computer vision algorithms, we can obtain location and property data for individual nanowires. Experimental results demonstrate the effectiveness of this method in automating nanodevice processing and improving fabrication efficiency.
Article
Physics, Applied
Kousik Bera, Dipankar Chugh, Hark Hoe Tan, Anushree Roy, Chennupati Jagadish
Summary: Wafer-scale thin films of hexagonal boron nitride have exceptional thermal and mechanical properties. The characteristics of substrates influence the physical and mechanical properties of these films. The roughness and height modulation at the surface of the substrates play a crucial role in determining substrate-mediated mechanical strain inhomogeneity in these films. Furthermore, there is a significant difference in the thermal evolution of strain in these films depending on substrate materials, with slippage playing a more significant role in 2 nm films than in 30 nm films.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Mohammad Rashidi, Tuomas Haggren, Chennupati Jagadish, Hark Hoe Tan
Summary: This research presents a hybrid nanolaser that supports both Fabry-Perot and random lasing modes. The study demonstrates different lasing properties of these modes, including wavelength, polarization, and coherency. Practical methods are introduced to distinguish these modes, and thermal tuning is used to switch between different laser types.
Article
Nanoscience & Nanotechnology
Tuomas Haggren, Vidur Raj, Anne Haggren, Nikita Gagrani, Chennupati Jagadish, Hoe Tan
Summary: This report demonstrates the construction of a hole-selective III-V semiconductor solar cell on i-GaAs using copper iodide (CuI) and optimization of the GaAs surface passivation and oxygen content of CuI, leading to high open-circuit voltage and solar conversion efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Tuomas Haggren, Julie Tournet, Chennupati Jagadish, Hark Hoe Tan, Jani Oksanen
Summary: A scalable multilayer epitaxial lift-off process is demonstrated, which allows efficient removal of epitaxially grown materials from their host substrate without external strains. The films retain good integrity after lift-off and can be further processed into devices. Cost analysis shows a 4-to-6-fold reduction in cost compared to the single-layer epitaxial lift-off process, making it significant for III-V photovoltaics and other technologies relying on thin-film III-V semiconductors.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Optics
Wei Wen Wong, Naiyin Wang, Chennupati Jagadish, Hark Hoe Tan
Summary: This study presents a novel approach to realize on-chip microlasers with directional emission in an all-dielectric, bottom-up grown material system. By coupling the laser emission into a vertical nanowire, efficient optical coupling is achieved and the emission directivity and side mode suppression can be improved by tuning the geometric parameters of the system.
LASER & PHOTONICS REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Jun-Wei Liao, Zhen-Ting Huang, Chia-Hung Wu, Nikita Gagrani, Hark Hoe Tan, Chennupati Jagadish, Kuo-Ping Chen, Tien-Chang Lu
Summary: In this study, localized surface plasmon lasing at room temperature in the communication band was achieved using metallic nanoholes as plasmonic nanocavity and InP nanowires as gain medium. Optimization of laser performance was demonstrated through coupling between two metallic nanoholes, allowing for manipulation of lasing properties. These plasmonic nanolasers offer lower power consumption, smaller mode volumes, and higher spontaneous emission coupling factors, making them promising for high-density sensing and photonic integrated circuits.
Article
Nanoscience & Nanotechnology
Bikesh Gupta, Doudou Zhang, Hongjun Chen, Chennupati Jagadish, Hark Hoe Tan, Siva Karuturi
Summary: This study presents a novel approach for fabricating high-performance solar cells based on InP heterojunctions using a solution-processed ferri-hydrite (Fh) electron-selective contact (ESC). The champion cell efficiency of 16.6% is achieved, which is a significant improvement over those from previous studies using other solution-processed ESC materials. The Fh layer not only selectively extracts photogenerated electrons from InP but also simultaneously serves as a surface protection layer, improving the cell's long-term stability.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Wei Wen Wong, Naiyin Wang, Bryan D. D. Esser, Stephen A. A. Church, Li Li, Mark Lockrey, Igor Aharonovich, Patrick Parkinson, Joanne Etheridge, Chennupati Jagadish, Hark Hoe Tan
Summary: In this study, we utilize the selective area epitaxy method to deterministically engineer thousands of microring lasers on a single chip. By elucidating a detailed growth mechanism and controlling the adatom diffusion lengths, we achieve ultrasmooth cavity sidewalls. These engineered devices exhibit a tunable emission wavelength in the telecommunication O-band and show low-threshold lasing with high device efficacy across the chip. This work marks a significant milestone toward the implementation of a fully integrated III-V materials platform for next-generation high-density integrated photonic and optoelectronic circuits.
Article
Chemistry, Physical
Sonachand Adhikari, Felipe Kremer, Mykhaylo Lysevych, Chennupati Jagadish, Hark Hoe Tan
Summary: GaN/AlGaN core-shell nanowires with various Al compositions have been grown on GaN nanowire array. The AlGaN shells have lower Al compositions than the gas phase input ratio. Defect-related luminescence has been observed in the AlGaN shells, with partial dislocations as the dominant defects. Growth of nonpolar m-plane AlxGa1-xN/AlyGa1-yN quantum wells on the sidewalls of the GaN nanowires shows excellent morphology and optical emission.
NANOSCALE HORIZONS
(2023)
