Article
Chemistry, Physical
Min Joo Park, Abu Bashar Mohammad Hamidul Islam, Yu-Jung Cha, Joon Seop Kwak
Summary: This study fabricated a-plane nanopillar LED based on nonpolar InGaN/GaN single quantum-well using a top-down fabrication method, with self-aligned In3Sn nanodots as etching masks. The fabricated nanopillars showed high yield and a large height-to-diameter aspect ratio as observed by scanning electron microscopy characteristics. The size of the nanopillars depended on the size of In3Sn nanodots, which were fabricated from ITO thin film using a 3% HCl solution.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Analytical
Yongkang Zhang, Zhongxuan Hou, Chaowei Si, Guowei Han, Yongmei Zhao, Xiaorui Lu, Jiahui Liu, Jin Ning, Fuhua Yang
Summary: The silicon etching process is crucial in semiconductor production, but undercutting is a nonideal effect. The desired undercut varies depending on the desired structure, with a reduced undercut preferred for good sidewall morphology and an enlarged undercut beneficial for microstructure tips. The choice of mask materials and the etching process can affect the undercut. This study compares the undercut effects caused by different mask materials (Cr, Al, ITO, SiNx, and SiO2) using isotropic etching and the Bosch process. The results show that the SiNx mask causes the largest undercut in the Bosch process, while the SiO2 mask causes the smallest. In the isotropic process, the results are reversed. The effect of charges in the mask layer is found to be responsible for this, with the effect of electron accumulation being negligible. Selecting appropriate mask materials can enhance or suppress the undercut effect, which is beneficial for the MEMS process. Finally, a tapered silicon tip with a top diameter of 119.3 nm is successfully fabricated using the isotropic etching process and an Al mask.
Article
Physics, Applied
Tianhao Jiang, Jian Wang, Jiaqi Liu, Meixin Feng, Shumeng Yan, Wen Chen, Qian Sun, Hui Yang
Summary: Semiconductor nano-membranes offer a new approach to improve the performance of optical devices. In this study, we present a fabrication method for GaN-based LED membranes, which includes the complete device structure including contact metals from Si substrate. The method involves electrochemical etching of the highly conductive AlN/Si interface, which is naturally formed in GaN-on-Si materials. Photoluminescence and Raman scattering spectra show reduced internal stress, and electrical measurements demonstrate decreased leakage current and series resistance, indicating the successful preservation of the whole structure.
APPLIED PHYSICS EXPRESS
(2022)
Article
Physics, Applied
Wai Yuen Fu, Hoi Wai Choi
Summary: A light-emitting bipolar transistor (LEBJT) has been developed by utilizing the existing LED structure to construct a PNP bipolar junction transistor, eliminating the need for customized structures or epitaxial regrowth. Two designs of GaN LEBJT were demonstrated, with one featuring a larger emitter area for electronic-optical signal conversion and another with a reduced emitter area for increased current gain.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Wen Chen, Meixin Feng, Yongjun Tang, Jian Wang, Jianxun Liu, Qian Sun, Xumin Gao, Yongjin Wang, Hui Yang
Summary: GaN-on-Si resonant-cavity light-emitting diodes (RCLEDs) were successfully fabricated through wafer bonding and Si substrate removal. The double-sided dielectric distributed Bragg reflectors formed a high-quality optical resonant cavity, showing good spectral characteristics. High data transmission rates and low-cost emitters make them advantageous for future visible light communications.
Article
Chemistry, Physical
Chang Liu, Yanghua Lu, Xutao Yu, Runjiang Shen, Zhemin Wu, Zunshan Yang, Yanfei Yan, Lixuan Feng, Shisheng Lin
Summary: In this work, the design of a Graphene/MoS2 heterostructure resulted in a highly efficient LED with enhanced carrier multiplication and increased light output. The addition of MoS2 increased the maximum external quantum efficiency by 61%.
Article
Physics, Multidisciplinary
Shunpeng Lu, Yiping Zhang, Ying Qiu, Xiao Liu, Menglong Zhang, Dongxiang Luo
Summary: The study found through simulated experiments that under low voltage conditions, increased temperature led to an increase in carrier concentration, improving the efficiency of the LED; while under high voltage, reduced temperature alleviating thermal droop further increased overall efficiency.
FRONTIERS IN PHYSICS
(2021)
Article
Chemistry, Analytical
Jovan Maksimovic, Haoran Mu, Daniel Smith, Tomas Katkus, Mantas Vaiciulis, Ramunas Aleksiejunas, Gediminas Seniutinas, Soon Hock Ng, Saulius Juodkazis
Summary: Ultra-short 230 fs laser pulses with a wavelength of 515 nm were used to create 0.4-1 μm holes in alumina Al2O3 etch masks with a thickness of 20-50 nm, simplifying the fabrication of high-efficiency solar cells. The conditions of laser ablation and the effects of sub-surface Si modifications were studied through plasma etching, numerical modeling, and minority carrier lifetime measurements. Mask-less patterning of Si using fs laser direct writing for dry plasma etching of Si was proposed.
Article
Chemistry, Physical
Junseok Jeong, Dae Kwon Jin, Joonghoon Choi, Junho Jang, Bong Kyun Kang, Qingxiao Wang, Won Il Park, Mun Seok Jeong, Byeong-Soo Bae, Woo Seok Yang, Moon J. Kim, Young Joon Hong
Summary: Remote epitaxy of GaN p-n homojunction microcrystals has been demonstrated for fabricating transferable, flexible white light-emitting diodes (WLEDs). The WLEDs show reliable performance even after repetitive bending and cycling temperature environments, making them suitable for flexible and modular light panels.
Article
Engineering, Electrical & Electronic
Annan Yang, Bin Yao, Zhanhui Ding, Rui Deng, Yongfeng Li
Summary: A white light-emitting diode (LED) based on the n-SrTiO3 (n-STO)/p-GaN heterojunction demonstrates good rectification characteristics and intense white light emission. The device exhibits strong and broad emission bands in both blue to red and ultraviolet to blue regions, originating from the p-type GaN and n-type STO layers respectively. This heterojunction structure shows promise for achieving LEDs with high intense white light emission.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Physical
Jiwei Chen, Jiangwen Wang, Keyu Ji, Bing Jiang, Xiao Cui, Wei Sha, Bingjun Wang, Xinhuan Dai, Qilin Hua, Lingyu Wan, Weiguo Hu
Summary: In this study, a flexible, stretchable, and transparent InGaN/GaN multiple quantum wells (MQWs)/polyacrylamide (PAAM) hydrogel-based light emitting diode is demonstrated, which is coupled with the piezo-phototronic effect. The quantum well energy band and integrated luminous intensity can be significantly modulated by external mechanical stimuli. The integration of inorganic semiconductor materials and organic hydrogel materials shows great potential in the development of stretchable optoelectronic devices and emerging wearable devices and virtual reality applications.
Article
Physics, Applied
Ziqian Qi, Linning Wang, Yingze Liang, Pengzhan Liu, Hongbo Zhu, Yongjin Wang
Summary: This article introduces a solar-blind full-duplex light communication system using 275-nm DUV LEDs, which eliminates electromagnetic interference and solar noise. The system allows a maximum communication distance of 7 meters and supports real-time video and file sharing.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Longxing Su, Yuqing Zuo, Jin Xie
Summary: This study utilized p-type GaN:Mg and n-type SnO(2) to fabricate a p-n heterojunction for applications in solar cells, dual-color light emitting diodes, and high-speed ultraviolet photodetectors, achieving an external quantum efficiency of up to 74%.
Article
Optics
Hui Wang, Guojiao Xiang, Yijian Zhou, Wenbo Peng, Yue Liu, Jiahui Zhang, Jinming Zhang, Rong Li, Yang Zhao
Summary: The influence of ambient temperature on the electrical characteristics of p-CuO/i-Ga2O3/n-GaN heterojunction diode was studied, showing typical diode rectification characteristics with high rectification ratios at different ambient temperatures. It was found that the temperature sensitivity of the forward current was greater than that of the reverse current at driving voltages of +/- 3V.
JOURNAL OF LUMINESCENCE
(2022)
Article
Engineering, Electrical & Electronic
G. Kalyon, S. Mutlu, F. Kuruoglu, I. Pertikel, I. Demir, A. Erol
Summary: We report an n-type In0.53Ga0.47As based Gunn light emitting diode operated at around 1.6 mu m. The device structure comprises of an n-type In0.53Ga0.47As epilayer with a thickness of 5 mu m grown by Metal Organic Vapour Phase Epitaxy (MOVPE) on a semi-insulating InP substrate and fabricated in a planar architecture with a stepped structure at anode side to suppress the destructive effect of high built-in electric field in propagating Gunn domain. Gunn diode is operated under pulsed voltage with a pulse width of 60 ns and pulse duration of 4.5 ns to keep the duty cycle as low as 0.0013%. The Gunn oscillations with an 1 ns period are observed at around 4.1 kV/ cm, which corresponds to the electric field threshold of Negative Differential Resistance (NDR). The light emission at around 1.6 mu m also starts at the threshold electric field of the NDR region (E = 4.2 kV/cm) of the current-voltage curve, and the emission intensity increases drastically with increasing applied electric field. The observed light emission at NDR threshold electric field where Gunn oscillations appear on the voltage pulse is attributed to the impact ionisation process occurring in the current domains along the sample, which generates excess carriers to initiate the band-to-band recombination in In0.53Ga0.47As.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Engineering, Environmental
Daniel Ocinski, Piotr Mazur
JOURNAL OF HAZARDOUS MATERIALS
(2020)
Article
Chemistry, Physical
A. Sabik, A. Trembulowicz, P. Mazur, G. Antczak
Article
Chemistry, Physical
M. Grodzicki, P. Mazur, A. Sabik
APPLIED SURFACE SCIENCE
(2020)
Article
Chemistry, Physical
Rafal Lewandkow, Radoslaw Wasielewski, Piotr Mazur
SURFACE REVIEW AND LETTERS
(2020)
Article
Nanoscience & Nanotechnology
P. V. Galiy, T. M. Nenchuk, A. Ciszewski, P. Mazur, Ya. M. Buzhuk, O. V. Tsvetkova
APPLIED NANOSCIENCE
(2020)
Article
Materials Science, Multidisciplinary
Damian Wojcieszak, Malgorzata Osekowska, Danuta Kaczmarek, Bogumila Szponar, Michal Mazur, Piotr Mazur, Agata Obstarczyk
Article
Engineering, Environmental
Irena Jacukowicz-Sobala, Daniel Ocinski, Piotr Mazur, Ewa Stanislawska, Elzbieta Kociolek-Balawejder
JOURNAL OF HAZARDOUS MATERIALS
(2020)
Article
Materials Science, Multidisciplinary
R. Lewandkow, M. Grodzicki, P. Mazur, A. Ciszewski
Article
Chemistry, Physical
Rafal Lewandkow, Milosz Grodzicki, Piotr Mazur, Antoni Ciszewski
Summary: Al2O3 insulator layers were deposited on n-type GaN(0001) surface by PVD method, characterized by XPS and UPS, with the result showing amorphous structure and calculated VBO of -1.3 eV for Al2O3/n-GaN(0001) interface.
SURFACE AND INTERFACE ANALYSIS
(2021)
Article
Chemistry, Multidisciplinary
P. V. Galiy, T. M. Nenchuk, A. Ciszewski, P. Mazur, V. I. Dzyuba, T. R. Makar
Summary: In this study, the formation of indium deposited coverage on the (001) surface of InTe layered semiconductor crystal due to solid state dewetting process was investigated using STM/STS in UHV. The results showed that the shape and arrangement of 0D indium induced nanostructures are influenced by the square surface lattice symmetry, and there is a correlation between indium coverage kinetics and the increase in the quantity of DOS within the band gap of InTe.
MOLECULAR CRYSTALS AND LIQUID CRYSTALS
(2021)
Article
Environmental Sciences
Daniel Ocinski, Joanna Augustynowicz, Konrad Wolowski, Piotr Mazur, Ewa Sitek, Jerzy Raczyk
Summary: The study identified three species of algae likely responsible for effective bioremediation of highly Cr(VI)-polluted habitats, showing characteristics of high chromium accumulation and detoxification mechanisms involving reduction and biosorption. With some modifications, the studied reservoir could potentially serve as a cost-effective bioreactor for reducing chromium concentration to desired levels.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Chemistry, Physical
Rafal Lewandkow, Piotr Mazur, Artur Trembulowicz, Agata Sabik, Radoslaw Wasielewski, Milosz Grodzicki
Summary: This paper explores the potential use of magnesium oxide layers as gate material for SiC MOSFET structures by investigating MgO/SiC(0001) and MgO/graphite/SiC(0001) systems in situ under ultrahigh vacuum. The MgO layers were obtained through reactive evaporation, with graphite layers formed through thermal annealing in UHV. Physicochemical properties were determined using X-ray and UV photoelectron spectroscopy, confirming the formation of MgO compounds and showing that the valence band maximum of MgO layers is deeper on graphitized surfaces compared to SiC(0001).
Article
Chemistry, Physical
Micha Mazur, Damian Wojcieszak, Artur Wiatrowski, Danuta Kaczmarek, Aneta Lubanska, Jaros law Domaradzki, Piotr Mazur, Ma lgorzata Kalisz
Summary: This paper analyzed the properties of tungsten oxide thin films prepared using the magnetron sputtering method. Changes in the Ar:O-2 gas mixture ratios were found to influence the structural, optical, and electrical properties of the deposited coatings significantly. The results suggest that controlling the gas atmosphere during sputtering can tailor the optoelectronic properties of tungsten oxide thin films, offering potential applications in transparent electronics.
APPLIED SURFACE SCIENCE
(2021)