Article
Nanoscience & Nanotechnology
Damanpreet Kaur, Rakhi, Pargam Vashishtha, Govind Gupta, Subhendu Sarkar, Mukesh Kumar
Summary: This study reports a simple and cost-effective method to enhance the device performance of amorphous gallium oxide thin film photodetectors by nanopatterning the surface. The formation of ripples on the surface leads to the creation of anisotropic conduction channels and an increase in surface defects, resulting in a reduction in device decay time and an improvement in device speed.
Article
Chemistry, Multidisciplinary
Xiaohu Hou, Xiaolong Zhao, Ying Zhang, Zhongfang Zhang, Yan Liu, Yuan Qin, Pengju Tan, Chen Chen, Shunjie Yu, Mengfan Ding, Guangwei Xu, Qin Hu, Shibing Long
Summary: The study proposes a defect and doping engineering strategy towards amorphous GaOX (a-GaOX) to achieve highly tolerant and ultra-sensitive solar-blind photodetectors for harsh environments, maintaining high performance even under high temperature or high voltage conditions.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Physical
Tong Su, Bohan Xiao, Zikang Ai, Lingjie Bao, Wencheng Chen, Yuheng Shen, Qijin Cheng, Kostya (Ken) Ostrikov
Summary: Most high-performance 8-Ga2O3 thin films are currently grown using expensive techniques such as molecular beam epitaxy, metal-organic chemical vapor deposition, and pulsed laser deposition. A custom-made plasma-enhanced chemical vapor deposition method is designed to achieve fast and cost-effective growth of 8-Ga2O3 thin films. The plasma-enhanced thermal oxidation process results in higher growth rates and improved film quality compared to traditional thermal oxidation methods.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Electrical & Electronic
Jianming Lei, Qing Cai, Jiying Cao, Tongchuan Ma, Jiandong Ye, Dunjun Chen
Summary: A high-performance epsilon-Ga2O3 solar-blind photodetector was successfully fabricated using an interdigital structure. The device exhibited a prominent response peak at 240 nm and a cutoff edge at 266 nm, with a solar-blind UV in-band/out-of-band rejection ratio of 10^5 and a photo-to-dark-current ratio exceeding 10^5. The impact of varying interdigital spacing on device performance was investigated, showing that decreasing spacing increased light current and responsivity, while increasing spacing reduced dark current.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Multidisciplinary
Huishan Wu, Tao Zhang, Leyun Shen, Yunze Liu, Fengzhi Wang, Jianguo Lu, Bin Lu, Xinhua Pan, Zhizhen Ye
Summary: A novel self-powered deep ultraviolet photodetector based on a SnS/Ga2O3 heterojunction modified by an ultrathin SnO layer has been developed. The device demonstrates remarkable photoelectric performance without any power supply, making it suitable for future optoelectronic applications.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Multidisciplinary
Zheng-Nan Li, Zhao-Cai Wang, Chen Li, Bao-Lin Lu, Wei Yan, Chen-Long Huang, Tao Zhang, Yin-Hong Luo, Ren-Kui Zheng
Summary: In this study, beta-Ga2O3 epitaxial thin films with different thicknesses were grown on Al2O3 (0001) substrates using the pulse laser deposition technology. The effects of film thickness on the properties and optoelectronic characteristics of the films were investigated.
Article
Materials Science, Multidisciplinary
Wencheng Chen, Xiangyu Xu, Minghang Li, Siliang Kuang, Kelvin H. L. Zhang, Qijin Cheng
Summary: In this work, a self-powered solar-blind photodetector with a fast response is achieved using a p-GaN/i-Ga2O3/n-Ga2O3 (pin) heterojunction. The device exhibits good self-powered characteristics, high responsivity, high photo-to-dark current ratio, and fast response speed. The interfacial electronic structure between p-GaN and i-Ga2O3 is studied in detail, revealing conduction band offset and valence band offset, which contribute to the excellent device performance.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Xiangyu Xu, Ziqian Sheng, Jueli Shi, Xin Chen, Yaxin He, Wenjing Xu, Xu Zhang, Duanyang Chen, Hongji Qi, Kelvin H. L. Zhang
Summary: The bandgap of (AlxGa1-x)(2)O-3 thin films can be modulated by varying the Al contents, resulting in high-performance photodetectors for solar-blind UV bands. The detection cut-off wavelengths and response peaks of the photodetectors can be tuned by changing the Al contents. The wide variations of the bandgap are mainly due to the upshift of the conduction band edges induced by Al 3s state hybridization.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Wenshan Chen, Xiangyu Xu, Jiaye Zhang, Jueli Shi, Jiawei Zhang, Wencheng Chen, Quin Cheng, Yuzheng Guo, Kelvin H. L. Zhang
Summary: This work reports the fabrication and performance of high performance solar-blind deep-UV photodetectors using (InxGa1-x)(2)O-3 thin films. The results show that controlling the In content in the films can achieve high sensitivity to solar-blind UV spectrum. Compared to Ga2O3, the (InxGa1-x)(2)O-3 films demonstrate enhanced performance due to the modulation of optical and electronic properties by In.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Physics, Applied
Anisha Kalra, Usman Ul Muazzam, R. Muralidharan, Srinivasan Raghavan, Digbijoy N. Nath
Summary: This Perspective discusses the current status and challenges of ultrawide bandgap (UWBG) semiconductor-based deep-UV photodetectors in real-world applications. It introduces a new comprehensive figure of merit to evaluate their performance by considering gain, noise, and bandwidth. The article also raises the question of whether these detectors will ever find significant applications and be used in space-borne platforms for deep-space imaging.
JOURNAL OF APPLIED PHYSICS
(2022)
Review
Materials Science, Multidisciplinary
Urvashi Varshney, Neha Aggarwal, Govind Gupta
Summary: The COVID-19 pandemic has led to increased use of UV-C sterilizing devices to combat the virus, but prolonged exposure to UV-C can have harmful effects on the environment and human health. It is crucial to monitor UV-C exposure intensity and limit radiation, while developing highly sensitive solar-blind UV photodetectors to mitigate potential health risks.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Materials Science, Multidisciplinary
Yiping Chen, Chaohong Zheng, Yiren Chen
Summary: The study focused on developing high-performance AlGaN-based solar-blind UV photodetectors and designing a discrete signal amplifier circuit for weak signal detection, ultimately leading to the successful development of a portable solar-blind UV detection system.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
Yan Yang, Weiming Liu, Tiantian Huang, Mengxia Qiu, Rui Zhang, Wanli Yang, Junbo He, Xin Chen, Ning Dai
Summary: Flexible sensors and photodetectors are important strategies for advanced devices, and the use of amorphous ALD-Ga2O3 thin films has shown promise in fabricating flexible solar-blind photodetectors (SBPDs). Decorating the ALD-Ga2O3 channels with MoS2 multilayers has been found to improve the photocurrent of SBPDs working in the deep ultraviolet region.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
Gaohui Shen, Zeng Liu, Chee-Keong Tan, Mingming Jiang, Shan Li, Yufeng Guo, Weihua Tang
Summary: A solar-blind UV photodetector array based on a metalorganic chemical vapor deposition-grown beta-Ga2O3 thin film is fabricated for optical communication application. The device demonstrates high performance with a significant photo-to-dark current ratio, high responsivity, high external quantum efficiency, high specific detectivity, and fast response time. The array shows good spectral selectivity and low background noise, enabling effective outputting of information signals in optical communication.
APPLIED PHYSICS LETTERS
(2023)
Review
Physics, Applied
Xiaohu Hou, Yanni Zou, Mengfan Ding, Yuan Qin, Zhongfang Zhang, Xiaolan Ma, Pengju Tan, Shunjie Yu, Xuanzhe Zhou, Xiaolong Zhao, Guangwei Xu, Haiding Sun, Shibing Lon
Summary: Research on gallium oxide for deep-ultraviolet solar-blind detection has attracted significant interest due to its unique material properties and potential applications. Various crystal phases and polymorphous Ga2O3-based solar-blind photodetectors have been studied, with a focus on enhancing performance through techniques such as doping and annealing. DUV imaging technologies based on Ga2O3 SBPDs are systematically summarized, demonstrating promising future prospects for applications.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Mahesh Kumar, Devender Kumar
Summary: The research utilizes the AMP variant of the ant colony optimization algorithm to overcome the problem of local optima in the gravitational search algorithm and improve the exploration ability of the search space. The proposed GSAMP algorithm is applied to fingerprint recognition for complete and latent fingerprints, showing superiority over other methods.
INTERNATIONAL JOURNAL OF MODERN PHYSICS C
(2023)
Article
Engineering, Chemical
Vijendra Singh, Selvamani Arumugam, Mahesh Kumar, Anup Prakash Tathod, Nagabhatla Viswanadham
Summary: The studies present an efficient vapor-phase continuous-flow process for the production of sustainable para-xylene (p-X)-enriched alkyl-aromatics from crude bioglycerol utilizing a ZSM-5 micro-mesoporous composite catalyst system. This process achieves 100% conversion of glycerol and produces liquid stock containing approximately 85% alkyl-aromatics, notably xylene isomers with around 57% p-X content, which is the highest reported thus far. The resulting liquid stock has potential applications in renewable petrochemicals, polymer production, and gasoline blending due to its low benzene content, high octane rating, and xylene-rich composition.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Inorganic & Nuclear
Archana Rana, Amit Kumar Chaudhary, Saurabh Saini, Ritu Srivastava, Mahesh Kumar, Shailesh Narain Sharma
Summary: The investigation of the lifetime of charge carrier dynamics in AgNPs nanomedicine is a current ongoing concern. Biosynthesis of AgNPs using Ocimum sanctum leaf extract results in spherical nanoparticles with a diameter of approximately 34 nm. AgNPs exhibit antibacterial activity against Xanthomonas Oryzae bacteria, the rice pathogen, and their charge carrier dynamics govern their efficacy against bacteria.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Physics, Condensed Matter
Sumit Kumar, Rajneesh Chaurasiya, Mustaque A. Khan, Gang Meng, Jen-Sue Chen, Mahesh Kumar
Summary: We developed a highly selective and sensitive H2S sensor based on CuO thin film, which was enhanced by decorating with rGO nanosheets. The CuO thin film was deposited using Chemical Vapor Deposition, and the sensing response was improved by forming heterojunctions with rGO. The developed sensor showed high selectivity towards H2S gas and the improvement in sensing response was attributed to increased hole concentration in CuO and increased absorption of H2S molecules.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Mathematics
Sergey A. Lobov, Alexey N. Mikhaylov, Ekaterina S. Berdnikova, Valeri A. Makarov, Victor B. Kazantsev
Summary: One challenge in modern neuroscience is creating a brain-on-a-chip, a device that can interact with the environment when integrated into a robot. This study proposes a mathematical model of a modular spiking neural network (SNN) to understand learning mechanisms in this context. The model shows that spike-timing-dependent plasticity, synaptic competition, and neuronal competition are all crucial for successful learning. The proposed solution has been tested in neuronal cultures and demonstrated the ability to establish associations between touch and ultrasonic sensors, allowing the robot to avoid obstacles.
Article
Chemistry, Analytical
Surajit Das, Ashok Kumar, Jitendra Singh, Mahesh Kumar
Summary: In this study, a p-NiO/n-SnO2 heterojunction-based formaldehyde (HCHO) sensor was fabricated by decorating the surface of pre-deposited SnO2 thin film with laser-ablated NiO nanoparticles. The gas sensing properties of the sensor were systematically investigated, and it showed a higher response towards 50 ppm HCHO compared to the pristine SnO2 sensor. The study demonstrated that laser ablation methods have great potential as a chemical-free surface decoration route for metal oxide heterojunction-based sensors.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Analytical
Amit Kumar Shringi, Amit Kumar, Maloy Das, Sang Sub Kim, Hyoun Woo Kim, Mahesh Kumar
Summary: Novel metal functionalization of semiconductor metal oxide surfaces can effectively improve the selectivity and sensitivity of gas sensors. In this study, the functionalization of α-Fe2O3 sensor with silver nanoparticles enhanced its sensing performance for NO2 molecules, resulting in a higher relative response rate.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Mathematics
Sergey V. Stasenko, Alexey N. Mikhaylov, Victor B. Kazantsev
Summary: This study investigates an unstructured neuron network model consisting of excitatory and inhibitory neurons, and explores the application of memristors with spike timing-dependent plasticity (STDP) characteristics in the network. The findings reveal that memristor-based STDP for inhibitory connections can suppress bursting dynamics and induce random spiking mode in the network. These results contribute to the advancement of invasive neurointerfaces and the understanding and control of epileptiform activity.
Article
Engineering, Multidisciplinary
Sergey V. Stasenko, Alexey N. Mikhaylov, Victor B. Kazantsev
Summary: We propose a new model for a neuromorphic olfactory analyzer based on memristive synapses. The model consists of receptive neurons that perceive various odors and decoder neurons that recognize these odors. Experimental results demonstrate that connecting these layers with memristive synapses allows the training of decoder neurons to recognize two types of odorants of varying concentrations. Without such synapses, the decoder neuron layer lacks specificity in odorant recognition. Odorant recognition occurs through the neural activity of a group of decoder neurons that have acquired specificity for the odorant in the learning process. The proposed phenomenological model highlights the potential use of memristive synapses in practical odorant recognition applications.
Article
Physics, Multidisciplinary
D. S. Korolev, A. N. Tereshchenko, A. A. Nikolskaya, A. N. Mikhaylov, A. I. Belov, D. I. Tetelbaum
Summary: The regularities of the influence of initial substrate orientation and annealing conditions on the intensity and temperature dependence of the D1 luminescence line for the p-type silicon samples implanted with silicon ions followed by subsequent annealing were studied. It was found that the luminescent properties of the samples depended on both surface orientation and annealing temperature. For a silicon sample with (111) surface orientation, under certain heat treatment conditions, an anomalous temperature dependence of the D1 line intensity was demonstrated with the appearance of a second maximum at temperatures around 80 K.
ST PETERSBURG POLYTECHNIC UNIVERSITY JOURNAL-PHYSICS AND MATHEMATICS
(2023)
Review
Materials Science, Multidisciplinary
Hamid Reza Ansari, Ali Mirzaei, Hooman Shokrollahi, Rahul Kumar, Jin-Young Kim, Hyoun Woo Kim, Mahesh Kumar, Sang Sub Kim
Summary: Flexible/wearable gas sensor technology is of great interest for its applications in personal environmental monitoring, healthcare, and safety. The use of two-dimensional (2D) materials, such as graphene and transition metal dichalcogenides (TMDs), in the development of flexible/wearable gas sensors has gained significant attention due to their excellent properties. This review discusses recent advancements in the field, including the sensing performance of 2D materials-based sensors on different substrates and their potential applications and challenges.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Multidisciplinary
Bidesh Mondal, Xiaolei Zhang, Sumit Kumar, Feng Long, Nirmal Kumar Katiyar, Mahesh Kumar, Saurav Goel, Krishanu Biswas
Summary: The demand for carbon-free energy sources has made the use of hydrogen (H2) gas increasingly important, but its explosive nature raises safety concerns. Researchers have developed a hydrogen gas detection sensor using high-entropy alloy nanoparticles, which shows high selectivity and sensitivity. By decorating the 2D MoS2 surface with these nanoparticles, the sensor can effectively adsorb and dissociate H2 gas, thereby improving its performance.
Article
Chemistry, Physical
Chayan Das, Ashok Kumar, Suresh Kumar, Neha V. Dambhare, Mahesh Kumar, Arup K. Rath, Satyajit Sahu
Summary: In recent years, there has been significant interest in two-dimensional transition metal dichalcogenides (2D-TMDC) due to their exceptional properties in generating excitons. Among them, two-dimensional molybdenum disulfide (MoS2) has been widely used in optoelectronic and photovoltaic applications. However, the original MoS2-based devices are not suitable for these applications due to their low performance. This study demonstrates that by decorating pristine MoS2 with reduced graphene oxide (rGO), the performance of the devices can be greatly improved in terms of dark current, photo-to-dark current ratio, and response time.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Sumit Kumar, Mustaque A. Khan, Shashank Shekhar Mishra, Rajneesh Chaurasiya, Nipun Sharma, Meng Gang, Chandra S. Tiwary, Krishanu Biswas, Mahesh Kumar
Summary: The development of new nanomaterials is crucial for improving the sensing performance of sensor devices. In this study, the gas sensing properties of two-dimensional quasicrystal (2D QC) nanosheets and WS2 nanoflakes were explored, revealing that the decoration of QC nanosheets on WS2 nanoflakes greatly enhances their sensing performance.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Review
Computer Science, Interdisciplinary Applications
Neeraj Goel, Kishor Kunal, Aditya Kushwaha, Mahesh Kumar
Summary: This article comprehensively covers different sensing mechanisms, parameters affecting sensitivity and selectivity, techniques to enhance gas sensing response, and future opportunities and challenges of metal oxide semiconductor-based gas sensors.
ENGINEERING REPORTS
(2023)