Article
Chemistry, Multidisciplinary
Jinyuan Xu, Ailing Chen, Linfeng Yu, Donghai Wei, Qikun Tian, Huimin Wang, Zhenzhen Qin, Guangzhao Qin
Summary: In this paper, the stable structure of a monolayer CuI with ultra-low thermal conductivity and an ultra-wide direct bandgap is predicted from first-principles calculations. This material shows potential applications in transparent and wearable electronics.
Article
Chemistry, Multidisciplinary
Meng-Hsin Chen, Bo-Wen Chen, Kai-Lun Xu, Vin-Cent Su
Summary: In this work, wide-angle capacity is integrated into vortex beams with a high topological charge through the engineering of a metasurface. Spiral patterns and their helicity alterations are meticulously investigated and analyzed, revealing a petal-like interference pattern and the achievement of design objectives. The importance of device angular capability is also emphasized.
Article
Nanoscience & Nanotechnology
Chuanliang Wang, Jinyang Cai, Xiaoqi Liu, Chunfeng Chen, Xiaoke Chen, Khadga Jung Karki
Summary: This study presents a simple and sensitive method based on the phase modulation of femtosecond pulses to quantify single-, two-, and three-photon absorptions in GaP and InGaN photodetectors. The results show that only three-photon absorption contributes to the photocurrent in the InGaN device when excited by femtosecond pulses at 1030 nm. On the other hand, single-, two-, and three-photon absorptions have comparable contributions in the GaP detector. Additionally, the method can be used to image the heterogeneity of multiphoton photocurrent in devices.
Article
Physics, Applied
Vineeta R. Muthuraj, Caroline E. Reilly, Thomas Mates, Shuji Nakamura, Steven P. DenBaars, Stacia Keller
Summary: The growth temperature of III-nitride films was lowered through MOCVD, allowing for heterogeneous integration with other semiconductor systems. By optimizing the flow conditions of disilane, high electron concentrations and low sheet resistances were achieved, expanding device design and process options for III-nitride-based electronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Vin-Cent Su, Shao-Yang Huang, Meng-Hsin Chen, Chia-Hung Chiang, Kai-Lun Xu
Summary: This study successfully fabricated infinite-OAM meta-knobs (IOMKs) with exceptionally high OAM modes of 32 and 16. The optical tunability of IOMKs was demonstrated by illuminating them with incident light possessing diverse degrees of freedom, including different polarizations and wavelengths. The interference nature of IOMKs was experimentally explored in interference eraser measurements, demonstrating their broadband capability and high reproducibility. These findings represent a significant step toward understanding the potential applications of IOMKs in quantum optics and their promising role in the generation of complex output states.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yahya Mohtashami, Larry K. Heki, Matthew S. Wong, Jordan M. Smith, Jacob J. Ewing, William J. Mitchell, Shuji Nakamura, Steven P. DenBaars, Jon A. Schuller
Summary: Researchers demonstrate metasurface LEDs that emit directional or focused light, showing advanced phase control technology. These metasurface LEDs exhibit better external quantum efficiency than unpatterned LEDs, providing possibilities for the development of high-efficiency metal-free LED devices.
Article
Chemistry, Analytical
Binlu Yu, Yumeng Luo, Liang Chen, Zhiqin Chu, Kwai Hei Li
Summary: The study introduces a novel, miniaturized, and easy-to-use optical sensor for accurate real-time humidity measurement. By integrating a photonic chip with an artificial opal layer, the sensor provides highly linear and repeatable response, large dynamic range, and fast response time, showing great potential for practical humidity-sensing applications.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Engineering, Electrical & Electronic
Yumeng Luo, Binlu Yu, Liang Chen, Kwai Hei Li
Summary: A micro humidity sensor based on a GaN chip with silica opal is fabricated, providing a linear relationship, compact size, low cost, high repeatability, and ease of integration and operation.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Physical
Lukasz Janicki, Ryszard Korbutowicz, Mariusz Rudzinski, Piotr Michalowski, Sebastian Zlotnik, Milosz Grodzicki, Sandeep Gorantla, Jaroslaw Serafinczuk, Detlef Hommel, Robert Kudrawiec
Summary: This study comprehensively investigates the structural and optical properties of GaN subjected to three oxidation modes. The results reveal that all modes lead to the growth of beta-phase Ga2O3, but they differ in surface morphology, growth rate, and oxygen diffusion behavior. Only the vapor oxidation process does not degrade the material underneath the oxide layer.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Muhammad Saddique Akbar Khan, Hui Liao, Guo Yu, Imran Iqbal, Menglai Lei, Rui Lang, Zehan Mi, Huanqing Chen, Hua Zong, Xiaodong Hu
Summary: Two innovative techniques, serpentine channel pattern sapphire substrate (SCPSS) and InGaN interlayer (IL), are proposed to effectively reduce threading dislocations (TDs) in GaN-based devices. Experimental results demonstrate the effectiveness of these techniques in decreasing the number of TDs and improving material quality.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Multidisciplinary
Junting Chen, Junlei Zhao, Sirui Feng, Li Zhang, Yan Cheng, Hang Liao, Zheyang Zheng, Xiaolong Chen, Zhen Gao, Kevin J. J. Chen, Mengyuan Hua
Summary: In this study, the GaN surface is converted into a GaON epitaxial nanolayer through a two-step oxidation-reconfiguration process, overcoming the vulnerability of the GaN surface and enhancing the stability and reliability of GaN-based devices. The GaON nanolayer derived from GaN possesses advantages such as a wide bandgap, high thermodynamic stability, and large valence band offset with a GaN substrate, which can be further utilized to improve the performance of GaN-based devices in various applications.
ADVANCED MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Wei Lin, Maojun Wang, Ruiyuan Yin, Jin Wei, Cheng P. Wen, Bing Xie, Yilong Hao, Bo Shen
Summary: The breakdown voltage of vertical GaN p-n diode is successfully boosted from 661V to 1489V using the HMSG-JTE technique, improving the electric field distribution and enhancing device performance.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Ali M. Khalifa, Ali H. Saleem, Hajer Z. Refaat, Naser M. Ahmed
Summary: The study investigated the sensing characteristics of undoped N-type GaN-based extended gate field effect transistor (EGFET) as a pH sensor, demonstrating good sensitivity and linearity. Unique current-voltage (I-V) characteristics with gate controllability were observed in the solution. Using six buffer solutions with a pH range of 2-12, the experiment showed a reference voltage sensitivity of 24.72 mV/pH.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shi Fang, Liuan Li, Weiyi Wang, Wei Chen, Danhao Wang, Yang Kang, Xin Liu, Hongfeng Jia, Yuanmin Luo, Huabin Yu, Muhammad Hunain Memon, Wei Hu, Boon S. Ooi, Jr-Hau He, Haiding Sun
Summary: This research reports a bipolar-junction photoelectrode with a gallium nitride (GaN) p-n homojunction nanowire array, operating in electrolyte, and demonstrating bipolar photoresponse controlled by different wavelengths of light. By rationally decorating the nanowires with a ruthenium oxide (RuOx) layer, guided by theoretical modeling, the resulting RuOx/p-n GaN photoelectrode exhibits significantly boosted bipolar photoresponse compared to the pristine nanowires. The loading of the RuOx layer optimizes surface band bending, promotes charge transfer, and enhances the efficiency of redox reactions, leading to improved positive and negative photocurrents. Lastly, a dual-channel optical communication system is constructed using only one photoelectrode to decode encrypted dual-band signals.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Zhe (A. ) Jian, Kai Sun, Stefan Kosanovic, Christopher J. Clymore, Umesh Mishra, Elaheh Ahmadi
Summary: Wafer bonding of β-Ga2O3 and N-polar GaN single crystal substrates, achieved by adding ZnO as a glue interlayer, resulted in fully bonded wafers without Newton rings. Temperature-dependent current-voltage measurements revealed the impact of post-annealing temperature on the electrical and structural characteristics of the bonded samples. Annealing the bonded wafers at 1100°C in N-2,N- environment consistently produced ohmic-like characteristics, attributed to the crystallization of ZnO and diffusion of Ga into ZnO. This work demonstrates promising wafer bonding of β-Ga2O3 and GaN, with potential applications in high-frequency and high-power devices.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Bogdan I. Tsykaniuk, Andrii S. Nikolenko, Viktor V. Strelchuk, Viktor M. Naseka, Yuriy I. Mazur, Morgan E. Ware, Eric A. DeCuir, Bogdan Sadovyi, Jan L. Weyher, Rafal Jakiela, Gregory J. Salamo, Alexander E. Belyaev
NANOSCALE RESEARCH LETTERS
(2017)
Article
Chemistry, Physical
Cyril Muehlethaler, Asami Odate, Jan L. Weyher, Igor Dziecielewski, John R. Lombardi
APPLIED SURFACE SCIENCE
(2018)
Article
Chemistry, Analytical
Malwina Liszewska, Bartosz Bartosewicz, Boguslaw Budner, Barbara Nasilowska, Mateusz Szala, Jan L. Weyher, Igor Dziecielewski, Zygmunt Mierczyk, Bartlomiej J. Jankiewicz
VIBRATIONAL SPECTROSCOPY
(2019)
Article
Chemistry, Physical
J. L. Weyher, B. Bartosewicz, I. Dziecielewski, J. Krajczewski, B. Jankiewicz, G. Nowak, A. Kudelski
APPLIED SURFACE SCIENCE
(2019)
Article
Engineering, Electrical & Electronic
B. Bartosewicz, Per Ola Andersson, I Dziecielewski, B. Jankiewicz, J. L. Weyher
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2019)
Article
Biophysics
Agata Kowalczyk, Jan Krajczewski, Artur Kowalik, Jan L. Weyher, Igor Dziccielewski, Malgorzata Chlopek, Stanislaw Gozdz, Anna M. Nowicka, Andrzej Kudelski
BIOSENSORS & BIOELECTRONICS
(2019)
Article
Physics, Applied
Tomasz Sochacki, Sakari Sintonen, Jan Weyher, Mikolaj Amilusik, Aneta Sidor, Michal Bockowski
JAPANESE JOURNAL OF APPLIED PHYSICS
(2019)
Article
Chemistry, Analytical
Omari Kirkland, Jan L. Weyher, John R. Lombardi
VIBRATIONAL SPECTROSCOPY
(2020)
Article
Multidisciplinary Sciences
Agata Bojarska-Cieslinska, Lucja Marona, Julita Smalc-Koziorowska, Szymon Grzanka, Jan Weyher, Dario Schiavon, Piotr Perlin
Summary: The study revealed that dislocation-related nonradiative recombination plays a significant role in structures with low indium content, particularly with edge dislocations being the main source. Additionally, long wavelength emitting structures showed higher average light intensity and better thermal stability, indicating shorter carrier diffusion paths limiting nonradiative recombination centers' impact.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Physical
J. L. Weyher, D. H. Van Dorp, T. Conard, G. Nowak, I. Levchenko, J. J. Kelly
Summary: Surface polarity plays a significant role in the chemical etching of GaN. Prior photoetching can cause the formation of nanocolumns and protrusions, which result in distinctive features depending on the crystal orientation and inhomogeneities presence.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Tomasz Sochacki, Robert Kucharski, Karolina Grabianska, Jan L. Weyher, Malgorzata Iwinska, Michal Bockowski, Lutz Kirste
Summary: This paper presents a detailed investigation into the basic ammonothermal growth process of GaN, focusing on the crystallization on a native seed with an intentionally varying off-cut. The study aims to answer fundamental questions related to the crystallographic planes, growth rates in different directions, and the influence of seed off-cut. Various characterization methods were employed, leading to the creation of a growth model for ammonothermal GaN crystal. The findings contribute to a better understanding of the basic crystal growth process of GaN using the ammonothermal method.
Article
Chemistry, Physical
Lutz Kirste, Thu Nhi Tran Thi Caliste, Jan L. Weyher, Julita Smalc-Koziorowska, Magdalena A. Zajac, Robert Kucharski, Tomasz Sochacki, Karolina Grabianska, Malgorzata Iwinska, Carsten Detlefs, Andreas N. Danilewsky, Michal Bockowski, Jose Baruchel
Summary: In this paper, a new type of extended defect in ammonothermally grown gallium nitride (GaN) single crystals, called hexagonal honeycomb shaped dislocation bundles, is investigated using X-ray Bragg diffraction imaging and defect selective etching. These dislocation bundles are either grouped in specific areas to form limited subgrain boundaries or aligned in straight long chains. The lattice distortions associated with these dislocation bundles are extensively measured to provide clues about their origin.
Article
Engineering, Electrical & Electronic
J. L. Weyher, A. Tiberj, G. Nowak, J. C. Culbertson, J. A. Freitas Jr
Summary: To control the electrical properties of SiC, it is important to understand the nature and properties of extended defects. In this study, traditional defect-selective etching and photo-etching methods were used to identify typical and new structural defects in commercial SiC wafers. The etch rate in photo-etching increases as the free carrier concentration decreases, allowing for more precise estimation of the carrier concentration.
JOURNAL OF ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Aleksandra Michalowska, Aleksandra Gajda, Agata Kowalczyk, Jan L. L. Weyher, Anna M. M. Nowicka, Andrzej Kudelski
Summary: The structure of chemisorbed layer on nanostructured GaN was determined using surface-enhanced Raman scattering (SERS) measurements. Hybridization of target single-stranded DNA with immobilized capture HS-ssDNA induced conformational changes in the chains of alkanethiol and mercaptohexan-1-ol. Silver substrates showed greater potential for observing these hybridization-induced rearrangements compared to gold substrates.
Article
Engineering, Electrical & Electronic
Yinqiu Shi, Denise Gosselink, Vladimir Y. Umansky, Jan L. Weyher, Zbig R. Wasilewski
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2017)
