Article
Physics, Applied
Shixiong Zhang, Ning Tang, Zhenhao Sun, Guoping Li, Teng Fan, Lei Fu, Yunfan Zhang, Jiayang Jiang, Peng Jin, Weikun Ge, Bo Shen
Summary: The correlation between spin-polarized carrier transfer and spin relaxation processes of a 2DEG in an InGaN/GaN quantum well is investigated. It is found that by tailoring the spin-orbit couplings, the spin relaxation time can be enhanced, which is significant for the development of GaN-based spintronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Pengfei Zhao, Ge Mu, Menglu Chen, Xin Tang
Summary: This study presents a simulation of colloidal quantum dot infrared detectors with monolithically integrated metal wire-grid polarizer and optical cavity. The results demonstrate that these detectors have high extinction ratio and improved light absorption, making them promising for high-performance infrared optoelectronic devices.
Article
Materials Science, Multidisciplinary
M. Vladimirova, S. Cronenberger, A. Colombier, D. Scalbert, V. M. Litvyak, K. V. Kavokin, A. Lemaitre
Summary: The heat capacity of the nuclear-spin system in GaAs-based microstructures is found to be higher than expected, and it is suggested that the quadrupole interaction induced by residual strain could be the additional reservoir for heat storage. Experimental results confirm this hypothesis and provide further understanding of the relation between mechanical strain and electric field gradients in GaAs.
Article
Optics
Shuyuan Zhang, Wei Liu, Jie Zhang, Hengyan Zhao, Zeyu Liu, Zhangbo Hu
Summary: The influence of the position of the InGaN layer on the electroluminescence properties of red InGaN/GaN single quantum well light-emitting diodes was numerically investigated. It was found that as the InGaN well shifts from the P-region to the N-region, the EL intensity decreases, and the spectrum red-shifts. The reduction in EL intensity is attributed to the enhanced injection efficiency of holes and weakened injection efficiency of electrons, resulting in a decrease in the total amount of carriers.
JOURNAL OF LUMINESCENCE
(2022)
Article
Physics, Condensed Matter
Seoung-Hwan Park
Summary: The built-in potential and ground state switching in coupled In0.2Ga0.8N/GaN quantum wires (QWRs) are investigated in relation to the barrier width between QWRs. For a relatively thin barrier thickness, the ground state wave function of the hole is observed in the upper QWR region, while that of the electron is observed in the lower QWR region. However, as the barrier width between QWRs increases, the difference in bottom energies between the lower and upper QWRs decreases, resulting in a ground state switching of the hole and electron wave functions for relatively thick barrier thickness.
SOLID STATE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Jiabin Cui, Somnath Koley, Yossef E. Panfil, Adar Levi, Nir Waiskopf, Sergei Remennik, Meirav Oded, Uri Banin
Summary: By synthesizing the smallest bow-tie nanoantenna and verifying its functionality using single-particle spectroscopy, as well as the formation of an electric-field hotspot at the structure center as predicted by theory, this structure can enhance emission polarization and serve as a photochemical reaction center.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Physics, Multidisciplinary
Wen-Jie Wang, Ming-Le Liao, Jun Yuan, Si-Yuan Luo, Feng Huang
Summary: The effects of GaN/InGaN asymmetric lower waveguide (LWG) layers on the photoelectrical properties of InGaN multiple quantum well laser diodes (LDs) were investigated theoretically. The optimal thickness and indium content of the InGaN insertion layer (InGaN-IL) in the lower waveguide were found to be 300 nm and 4% respectively. The thickness of the InGaN-IL mainly affects the output power and optical field distribution, and the highest output power achieved was 1.25 times that of the reference structure.
Article
Physics, Condensed Matter
Rui Li, Mingsheng Xu, Chengxin Wang, Shangda Qu, Kaiju Shi, Changfu Li, Xiangang Xu, Ziwu Ji
Summary: Experimental results show that different growth temperatures of InGaN/GaN multiple quantum wells can affect the structure and performance of LEDs, reducing the growth temperature can alter the structure and enhance the luminous efficiency.
SUPERLATTICES AND MICROSTRUCTURES
(2021)
Article
Engineering, Multidisciplinary
Du Jinjuan, Xu Shengrui, Peng Ruoshi, Fan Xiaomeng, Zhao Ying, Tao Hongchang, Su Huake, Niu Mutong, Zhang Jincheng, Hao Yue
Summary: In this study, InGaN/GaN multiple quantum-well structures were successfully grown on a c-plane GaN template with SiO2 stripe patterns along different directions as masks. The optical characteristics were found to be enhanced by the air-void structure and inclined semipolar quantum-well sidewalls, with the structure grown along the [1-100] orientation exhibiting less stress and higher PL intensity. Research using scanning electron microscopy and transmission electron microscopy provided insights into the anisotropic growth characteristics and formation of air voids.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2021)
Article
Optics
Mirsaeid Sarollahi, Pijush K. Ghosh, Manal A. Aldawsari, Shiva Davari, Malak Refaei, Reem Alhelais, Yuriy Mazur, Morgan E. Ware
Summary: Graded InGaN structures were designed by increasing indium composition, forming a Zig-Zag quantum well with broadband emission shifting to lower energies. The lowest energy band-to-band transition shifts noticeably with higher indium content, making the structure useful in optoelectronic devices.
JOURNAL OF LUMINESCENCE
(2021)
Article
Physics, Applied
Shixiong Zhang, Ning Tang, Xingchen Liu, Xiaoyue Zhang, Lei Fu, Yunfan Zhang, Teng Fan, Zhenhao Sun, Weikun Ge, Bo Shen
Summary: The spectrally distinguished spin relaxation dynamics in a single GaN/Al0.1Ga0.9N quantum well were investigated using time-resolved Kerr rotation spectrum at room temperature. Three distinct spin relaxation processes were observed, with different relaxation times for electrons in GaN quantum well and Al0.1Ga0.9N barrier layer due to the polarization electric field at the heterointerface. The dominant role of electron-photon scattering and alloy disorder scattering in the anisotropic D'yakonov-Perel' (DP) relaxation was revealed for electrons in bulk GaN and Al0.1Ga0.9N.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Y. C. Chow, C. Lynsky, S. Nakamura, S. P. DenBaars, C. Weisbuch, J. S. Speck
Summary: Differential carrier lifetime measurements were conducted on c-plane InGaN/GaN LEDs of different QW indium compositions, showing that doped barriers can reduce the internal electric field and improve electron-hole wavefunction overlap. LEDs with higher indium composition demonstrate better performance despite the introduction of more non-radiative recombination centers.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Yutian Lin, Xin Chen, Jianqi Dong, Chenguang He, Wei Zhao, Zhitao Chen, Kang Zhang, Xingfu Wang
Summary: This study demonstrates the preparation of freestanding InGaN/GaN quantum-wells membrane and optimization of the emission intensity and polarization characteristics in vertical devices by introducing the Piezo-phototronic effect. Under external straining, the EL intensity of the LED is significantly increased, and the polarization ratio of emission light is adjusted. The polarization ratio of photoresponse current in PD also shows significant changes under different strain conditions.
Article
Chemistry, Multidisciplinary
Slawomir P. Lepkowski
Summary: In this study, the quantum spin Hall effect in InN/InGaN coupled multiple quantum wells is theoretically studied. It is found that a topological insulator can be achieved in triple quantum wells when the In content in the interwell barriers is greater than or equal to the In content in the external barriers. In quadruple quantum wells, a topological insulator phase can only be achieved when the In content in the interwell barriers is larger than in the external barriers.
Article
Optics
Samadrita Das, Trupti Ranjan Lenka, Fazal Ahmed Talukdar, Sharif Md Sadaf, Ravi Teja Velpula, Hieu Pham Trung Nguyen
Summary: This paper presents the use of alternate pairs of InGaN/GaN prestrained layers with varying indium compositions in a light-emitting diode (LED) nanostructure to enhance its optical characteristics. The designed device shows improved efficiency and minimized efficiency droop compared to conventional LEDs, with high luminous power and minimal blueshift in the spectral range.
Article
Engineering, Electrical & Electronic
Shuhan Yang, Changzheng Sun, Bing Xiong, Jian Wang, Hao Zhibiao, Yanjun Han, Lai Wang, Hongtao Li, Jiadong Yu, Yi Luo, Yoshiaki Nakano
Summary: This study demonstrates the implementation of gain-coupled 4 x 56 Gb/s electroabsorption modulated laser (EML) arrays through the optimization of bonding-wire length, achieving modulation bandwidth over 40 GHz and low microwave reflection. Clear eye opening under 56 Gb/s nonreturn-to-zero (NRZ) modulation and transmission through 10 km single-mode fiber (SMF) have been successfully achieved.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2022)
Article
Physics, Applied
Jiadong Yu, Lai Wang, Jian Wang, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Hongtao Li
Summary: Temperature-dependent photoluminescence (TDPL) is commonly used to evaluate the internal quantum efficiency (IQE) of light-emitting semiconductors. However, this study found that TDPL is not reliable for InGaN quantum well samples with high threading dislocation density (>10(10) cm(-2)). Power-dependent photoluminescence (PDPL) must be used to confirm the IQE at low temperature and calibrate the TDPL values. A phenomenological model is proposed to explain the relationship between IQE and threading dislocation density.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Applied
Jiadong Yu, Zixuan Zhang, Yi Luo, Jian Wang, Lai Wang, Xiang Li, Zhibiao Hao, Changzheng Sun, Yanjun Han, Bing Xiong, Hongtao Li
Summary: This study reports the fabrication of high-quality gallium nitride (GaN) films using the ICP-MOCVD method at a low temperature. The GaN films were then used to produce thin-film transistors and photodetectors. The results show that these films exhibit excellent performance, demonstrating their potential for electronic device fabrication.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
Jiyuan Zheng, Xingjun Xue, Cheng Ji, Yuan Yuan, Keye Sun, Daniel Rosenmann, Lai Wang, Jiamin Wu, Joe C. Campbell, Supratik Guha
Summary: By replacing a fixed quenching resistor with a bias-dependent adaptive resistive switch, the recovery speed and frequency response of single-photon avalanche diodes can be significantly improved.
NATURE COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Jun Deng, Jiadong Yu, Zhibiao Hao, Jianbin Kang, Boyang Lu, Lai Wang, Changzheng Sun, Yanjun Han, Bing Xiong, Jian Wang, Hongtao Li, Yi Luo
Summary: We have demonstrated an optically pumped single-photon emitter operating at room temperature, which is based on disk-shaped GaN/AlN quantum dots embedded in a nanowire. The emitter has excellent optical properties and can be used as a potential light source for quantum information technologies. The study provides theoretical calculations and measurements that confirm the superior performance of the quantum dots, and the emitter shows high-order correlations at room temperature. This work offers a promising approach for realizing high-performance single-photon emission devices for quantum information technology.
ACS APPLIED NANO MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Xuecheng Liu, Bing Xiong, Changzheng Sun, Zhibiao Hao, Lai Wang, Jian Wang, Yanjun Han, Hongtao Li, Yi Luo
Summary: This letter presents a velocity-matched TFLN modulator based on low-loss capacitively-loaded traveling-wave electrodes (CL-TWEs) with an on-chip terminal resistor. The effect of termination resistance on the E-O frequency response is analyzed theoretically and confirmed experimentally. The results show that an ultra-flat E-O response can be achieved with a termination resistance slightly lower than the characteristic impedance of the CL-TWEs.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yunwei Ma, Ming Xiao, Zhonghao Du, Lei Wang, Eric Carlson, Louis Guido, Han Wang, Lai Wang, Yi Luo, Yuhao Zhang
Summary: This study addresses the activation of buried p-GaN layers in emerging GaN devices. It is found that the breakdown E-field and leakage current of sidewall-activated p-GaN layer are determined by the edge area with the highest activation efficiency. The leakage mechanism follows the trap-assisted tunneling model. These findings provide critical information for the design and processing of advanced GaN devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Physics, Applied
Boyang Lu, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Jian Wang, Hongtao Li, Lai Wang
Summary: In this study, a simplified trap-assisted tunneling model is established to explain the experimental results by considering the energy distribution on trap states. The nonuniform distribution of diffused p-type dopants is identified as the cause of abnormal photocurrent experimental results.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Ruo-Chen Zhao, Zhi-Biao Hao, Lai Wang, Jian Wang, Bing Xiong, Chang-Zheng Sun, Yan-Jun Han, Hong-Tao Li, Ning Zhuo, Feng-Qi Liu, Yi Luo
Summary: A novel InGaAs/AlInAs quantum cascade detector (QCD) with localized electric field is proposed, which achieves 40% higher extraction efficiency of photon-induced electrons compared to conventional QCDs. The localized electric field, induced by modulation doping, greatly influences the electron transport by extending the regulation of electronic states in quantum wells. The extraction efficiency is enhanced by enlarging the transition matrix element related to the extraction process. The proposed mid-IR QCD exhibits a peak responsivity of 156.9 mA/W and a Johnson noise limited detectivity of 1.9 x 1011 Jones at 80K.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Optics
Yuxin Tian, Bing Xiong, Changzheng Sun, Zhibiao Hao, Jian Wang, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, Yi Luo
Summary: Novel back-illuminated modified uni-traveling-carrier photodiodes (MUTC-PDs) with wide bandwidth and high saturation power are demonstrated. The effect of cliff layer doping on the electric field distribution is investigated to achieve fast carrier transport. MUTC-PDs with miniaturized device diameter and low contact resistance are fabricated to improve the RC-limited bandwidth. Meanwhile, inductive peaking is implemented to further extend the bandwidth. PDs with 3-pm and 3.6-pm-diameter exhibit a ultrawide bandwidth of 230 GHz and 200 GHz, together with -4.94 dBm and -2.14 dBm saturation power at 220 GHz and 200 GHz, respectively.
Letter
Optics
Zhaoqin He, Changzheng Sun, Bing Xiong, Jian Wang, Zhibiao Hao, Lai Wang, Yanjun Han, Hongtao Li, Lin Gan, Yi Luo
Summary: The dispersion characteristics of a microresonator are crucial for nonlinear optics applications. This study presents a simple and convenient method for measuring the dispersion profile of high-quality-factor GaN microrings using a single-mode fiber ring. The proposed method accurately determines the dispersion parameters by polynomial fitting based on the microresonator dispersion profile, which is further verified with frequency comb-based spectroscopy. The obtained dispersion profiles from both methods agree well with simulations.
Article
Optics
Haoqiang Wang, Yi Luo, Hongtao Li, Zihan Zang, Yunpeng Xu, Yanjun Han, Changzheng Sun, Zhibiao Hao, Lai Wang, Bing Xiong, Jian Wang, Lin Gan
Summary: In this paper, an extended ray-mapping method is proposed that incorporates differentiable ray-tracing into the design pipeline, allowing for accurate surface construction and efficient shape correction. The method involves two optimization stages and has successfully designed non-paraxial and off-axis illumination lenses in a short time. Simulation results demonstrate the effectiveness and robustness of the approach.
Article
Nanoscience & Nanotechnology
Xu Han, Jiadong Yu, Peilong Yang, Bo Liu, Xun Wang, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Jian Wang, Hongtao Li, Lai Wang
Summary: Remote epitaxy via graphene has potential for epi-layer mechanical exfoliation, but the stability of graphene during epitaxy is crucial. N-2 carrier gas is found to be the better choice for protecting graphene during annealing experiments. The graphene transition layer can remain stable during low-temperature buffer growth, but recrystallization of buffer layers at higher temperatures destroys the graphene transition layer, preventing exfoliation of epi-layers.
ACS APPLIED NANO MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Xu Han, Jiadong Yu, Zhenhao Li, Xun Wang, Zhibiao Hao, Yi Luo, Changzheng Sun, Yanjun Han, Bing Xiong, Jian Wang, Hongtao Li, Yuantao Zhang, Bin Duan, Jing Ning, Haidi Wu, Lai Wang
Summary: The remote epitaxy of GaN via graphene has significant research value in metal-organic chemical vapor deposition. It was found that suitable growth temperature, carrier gas, and substrate are essential for the successful exfoliation of GaN epitaxial layers.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
