Article
Materials Science, Ceramics
Marek Bouska, Virginie Nazabal, Jan Gutwirth, Tomas Halenkovic, Petr Nemec
Summary: Radio-frequency magnetron co-sputtering technique was employed to deposit Ge-Sb-Te amorphous thin films, covering a broad range of chemical composition. Large variations in electrical and optical contrast were observed upon annealing-induced crystallization, with the importance of GeTe content in Ge-Sb-Te thin films confirmed.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Justin Ryan Phelps, Ashwin Kumar Saikumar, Reza Abdolvand, Kalpathy B. B. Sundaram
Summary: This study reports the material properties of gallium-doped zinc oxide grown from a high impulse magnetron sputtering system (HiPIMS) and compares them to those of radio frequency (RF) sputtering deposition. The results show that HiPIMS and RF processes yield similar outcomes under the same average power conditions. RF depositions exhibit slightly higher band gap and deposition rate, as well as lower resistivity and optical absorption coefficient. Both methods show that band gaps and grain size increase with deposition power.
Article
Engineering, Electrical & Electronic
Kang Ling, Kuangkuang Li, Ruyu Bai, Bowen Zhao, Xingzhao Liu
Summary: Based on the prospects and needs in industrial, biological, and environmental monitoring fields, there is an urgent demand for the development of high-performance deep-ultraviolet photodetectors. This study successfully grew v thin films on c-plane sapphire substrates and fabricated v photodetectors based on a metal-semiconductor-metal structure, demonstrating fast overall response time, excellent performance characteristics, and high selectivity.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Optics
Zhou Lu, Xin Lv, Quan Xie
Summary: Thin transparent semiconductor films of GaMgZnO were prepared on quartz glass substrates using magnetron sputtering technique. The effects of sputtering pressure on the crystallization, micro-structure, electrical and optical features of the films were investigated. The results showed that sputtering pressure significantly influenced the structure and electro-optical characteristics of the films, with the sample prepared under a pressure of 3.6 Pa exhibiting the best quality and performance.
Article
Materials Science, Multidisciplinary
Chukwudi E. Iheomamere, Corey L. Arnold, Urmilaben P. Rathod, Khalil D. Omotosho, Andrey A. Voevodin, Nigel D. Shepherd
Summary: Spectroscopic and electrical studies of ZnO thin films grown by radio frequency magnetron sputtering at low power without substrate heating revealed improved stoichiometry and reduced free carrier concentration with increasingly energetic growth conditions. Hall measurements showed decreases in carrier concentration as power increased and deposition pressure decreased. These findings were well correlated with XRD, x-ray photoelectron spectroscopy, and photoluminescence results.
Article
Crystallography
Zegang Ni, Yuan Zhong, Xingfu Tao, Wei Li, Huifang Gao, Yan Yao
Summary: This study investigates the effects of radio frequency (RF) bias on the structural and mechanical properties of Niobium (Nb) films deposited on silicon substrates by magnetron sputtering. The results demonstrate that the RF bias can alter the crystal distribution, grain size, and lattice parameter of the films, leading to changes in their mechanical properties. The study aims to enhance the mechanical properties of Nb films deposited by RF-biased sputtering, expanding their potential application as protective coatings for medical implants.
Article
Chemistry, Physical
Xinlu Lin, Yufeng Zhang, Ziyao Zhu, Qiuchen Wu, Xiangxin Liu
Summary: The study highlights that deposition parameters can affect the growth rate and morphology of ZnTe films; the copper atomic concentration has an impact on the optical, structural, and electrical properties of ZnTe films; ZnTe can be used as a buffer layer for back contact to CdTe solar cells.
CHEMICAL PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Zhenxue Zhang, Mikdat Gurtaran, Xiaoying Li, Hio-Ieng Un, Yi Qin, Hanshan Dong
Summary: In this study, N-type and P-type BiTe-based thin films were deposited on silicon, glass, and Kapton HN polyimide foil using magnetron sputtering technique. The morphology, microstructure, and phase constituents of the thin films were characterized by SEM/EDX, XRD, and TEM. The electrical conductivity, thermal conductivity, and Seebeck coefficient were measured by an advanced in-plane test system. The power output (open-circuit voltage and electric current) of the thin films was measured at different temperature gradients using a custom-built apparatus. The impact of deposition parameters and the dimensions of the thin films on the power output were investigated to optimize the thin-film flexible TE device for thermal energy harvesting.
Article
Materials Science, Coatings & Films
Tomasz Wojcik, Vincent Ott, Sedat Oezbilen, Harald Leiste, Sven Ulrich, Paul Heinz Mayrhofer, Helmut Riedl, Michael Stueber
Summary: Transition metal diboride-based thin films have attracted strong interest in both fundamental and applied research. This study investigated the constitution and microstructure of multilayer thin films composed of TiBx and NiAl, and found that the nature of the interfaces has an impact on dislocation density and the ability to form dislocations in these multilayer structures.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Chemistry, Multidisciplinary
Ovidiu Toma, Vlad-Andrei Antohe, Ana-Maria Panaitescu, Sorina Iftimie, Ana-Maria Raduta, Adrian Radu, Lucian Ion, Stefan Antohe
Summary: ZnSe thin films were deposited by RF magnetron sputtering onto optical glass substrates under specific conditions. Structural, morphological, optical, and electrical characterizations were performed, revealing optimal sputtering conditions and electrical conduction behavior in the presence of an exponential trap distribution in the band gap of the ZnSe thin films. These results highlight the potential of ZnSe thin films as environmentally-friendly alternatives for Cd-free window layers in photovoltaic cell manufacturing.
Article
Chemistry, Multidisciplinary
Rajib Sahu, Dimitri Bogdanovski, Jan-Ole Achenbach, Siyuan Zhang, Marcus Hans, Daniel Primetzhofer, Jochen M. Schneider, Christina Scheu
Summary: The direct formation of MoB MBene domains in MoAlB thin film by Al deintercalation from MoAlB in the vicinity of AlOx regions is reported. Based on these results, a straightforward processing pathway for the direct formation of MoB MBene-AlOx heterostructures without employing chemical etching is proposed.
Article
Crystallography
He Gao, Shijian Wang, Da Xu, Xueshen Wang, Qing Zhong, Yuan Zhong, Jinjin Li, Wenhui Cao
Summary: In this study, a comprehensive analysis was conducted on the properties of DC magnetron sputtered Nb films fabricated with constant power at the National Institute of Metrology (China). The results showed that the stress and other parameters of the films can maintain a relatively stable state under constant power and Ar pressure.
Article
Physics, Condensed Matter
Emre Sener, Ozkan Bayram, Ugur Cem Hasar, Onder Simsek
Summary: The annealing temperature significantly affected the crystallite size and optical transmittance of ZnO thin films, with the crystallite size decreasing as the temperature increased. The transmittance of ZnO thin films ranged from 85% to 95% at a wavelength of 550 nm.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Ceramics
N. Jalalian Karazmoudeh, M. Soltanieh, M. Hasheminiasari
Summary: In this study, pure and zinc-doped copper oxide thin films were successfully deposited on a glass substrate using reactive magnetron sputtering. The effects of oxygen/argon ratio and dopant dosage on the structure, morphology, and topography of the films were analyzed. It was found that different oxygen partial pressures resulted in the formation of different phases of copper oxide, and doping with zinc affected the crystal structure and cell volume of the films. The applied RF power and Zn concentration also influenced the cationic ratio and surface roughness of the films, respectively. However, the grain size was not significantly affected by Zn doping.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Coatings & Films
B. C. Bussell, P. N. Gibson, J. Lawton, P. Couture, M. K. Sharpe, J. England, S. J. Hinder, V. Stolojan, S. A. Thornley, M. A. Baker
Summary: Aluminium-doped ZnO (AZO) thin films were deposited by remote plasma sputtering and their microstructure, chemical composition, and residual stress were investigated. The films exhibited optimum resistivity and optical transmittance at a specific RF plasma power of 1.5 kW. Factors such as grain size, orientation, and preferential sputtering affected the film properties.
SURFACE & COATINGS TECHNOLOGY
(2022)
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
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
Optics
Khosro Zangeneh Kamali, Lei Xu, Nikita Gagrani, Hark Hoe Tan, Chennupati Jagadish, Andrey Miroshnichenko, Dragomir Neshev, Mohsen Rahmani
Summary: Metasurfaces with dynamic tunability in their optical behaviour are highly desired for various applications. In this study, we demonstrate electrically tunable metasurfaces driven by thermo-optic effect and flash-heating in silicon. The device allows for video frame rate optical switching over multiple pixels and is compatible with modern electronic display technologies. It shows advantages such as large modulation depth, low optical loss, low input voltage requirement, and high switching speed.
LIGHT-SCIENCE & APPLICATIONS
(2023)
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
Multidisciplinary Sciences
Feng Zhou, Hehe Gong, Ming Xiao, Yunwei Ma, Zhengpeng Wang, Xinxin Yu, Li Li, Lan Fu, Hark Hoe Tan, Yi Yang, Fang-Fang Ren, Shulin Gu, Youdou Zheng, Hai Lu, Rong Zhang, Yuhao Zhang, Jiandong Ye
Summary: In this study, NiO/Ga2O3 heterojunctions with smaller reverse recovery, higher switching speed, and a robustness competitive to that of conventional homojunctions were reported. Avalanche and surge robustness involve fundamental carrier dynamics under high electric field and current density, and are prerequisites for power devices in power electronics applications. The heterojunction formed between n-type gallium oxide and p-type nickel oxide breaks the trade-off between robustness and switching speed in conventional homojunctions, and removes a key hurdle to advance ultra-wide bandgap semiconductor devices for power industrial applications.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yifan Jiang, Rui Shen, Tong Li, Jiamin Tian, Shuo Li, Hark Hoe Tan, Chennupati Jagadish, Qing Chen
Summary: This study systematically investigates the effect of Y2O3 coating on the performance of InAs NW FETs. The Y2O3 coating can reduce hysteresis, subthreshold swing, and on-state resistance, while increasing field-effect mobility and the on-off ratio. Furthermore, the stacking with HfO2 dielectric can provide better gate control and lower interface trap density.
Article
Biochemical Research Methods
Yonghwan Lee, Bikesh Gupta, Hark H. Tan, Chennupat Jagadish, Jihun Oh, Siva Karuturi
Summary: This article presents a protocol for preparing thin semiconductors and describes their application in photoelectrochemical water-splitting for hydrogen fuel production.
