Article
Materials Science, Multidisciplinary
Alex J. Grede, Noel C. Giebink
Summary: An analytical model for ideal organic laser diodes is introduced, based on the argument that their intrinsic active layers necessitate operation in the bipolar space charge-limited current regime. This study establishes a foundation for the development of organic laser diode technology by providing expressions for threshold current and voltage, and an analytical bound for laser operation in the presence of annihilation and excited-state absorption losses.
Article
Engineering, Electrical & Electronic
Ying Bin Zhu, Mei Yan Liao, Ruo He Yao
Summary: The properties of space charge limited current and induced particle reflection with a time-varying current injection have been investigated using a grid-free numerical approach. It has been found that the limiting current strongly depends on the current frequency, magnitude, and electron emission velocity. The dc component of the limiting current is approximately half of that obtained from the time-independent model in the low-frequency limit.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Polymer Science
Muhammad Shoaib Bhutta, Shakeel Akram, Pengfei Meng, Jerome Castellon, Serge Agnel, Hui Li, Yecai Guo, Ghulam Rasool, Shahid Hussain, Muhammad Tariq Nazir
Summary: The study observed steady-state electrical conduction current for single and multilayer polyimide (PI) nanocomposite films at different temperatures, finding that the dominant conduction mechanisms were space charge limited current (SCLC) and Poole-Frenkel current. At high electric fields, ohmic conduction was replaced by current-voltage dependency. Nanocomposite films exhibited higher conduction current at lower temperatures, but it declined at higher temperatures.
Article
Engineering, Chemical
Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im
Summary: The study focuses on understanding the behaviors of photogenerated charge carriers in polymer solar cells by estimating the charge-carrier photogeneration and extraction dynamics under different conditions. By comparing the maximum photocurrent densities and quantum efficiencies, insights into charge-carrier collection efficiency were obtained.
FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Electrical & Electronic
Johannes Bergur Gunnarsson, Kristinn Torfason, Andrei Manolescu, Agust Valfells
Summary: This study numerically simulates the classical charge dynamics in a microscopic planar vacuum diode with a finite emitter area and a finite number of electrons in the gap. The results are compared to the conventional 2-D Child-Langmuir and explain its limitations for submicrometer diameter emitters. Some simple relations are offered to understand space-charge limited flow from very small emitters.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Multidisciplinary
Mengmeng Bai, Yanqing Zhao, Shuting Xu, Tao Tang, Yao Guo
Summary: An alternative mechanism for THz current rectification is proposed, based on asymmetric bias-induced barrier lowering in common semiconductors. Geometric diodes, utilizing geometric asymmetry, demonstrate robust current rectification ability.
COMMUNICATIONS PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Ying Bin Zhu, Mei Yan Liao, Pan Zhao, Ruo He Yao
Summary: This article introduces a self-consistent model to study the space charge limited bipolar flow for 2-D nonuniform and uniform current injection, simultaneously determining the unknown current densities and potential distribution. By investigating a planar diode with a finite-width beam, the article observes nonuniform current density profiles due to edge effects. The enhancement factor follows a scaling with W/D ratio and gradually converges to the 1-D enhancement factor with increasing W/D ratio.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Physics, Multidisciplinary
Oles Matsyshyn, Francesco Piazza, Roderich Moessner, Inti Sodemann
Summary: By combining the techniques of nonequilibrium Green functions and Floquet theory, we demonstrate the existence of a well-defined periodic steady state leading to finite rectified currents in the weak coupling to a thermal bath regime. In this Rabi regime, the rectified current scales as the square root of the radiation intensity, allowing for easy diagnosis in experiments. Moreover, our description provides a smooth interpolation from ideal periodic Gibbs ensemble describing Rabi oscillations to the perturbative regime with rapid relaxation due to strong coupling to a thermal bath.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Mei Yan Liao, Ruo He Yao, Ying Bin Zhu
Summary: This paper proposes a numerical iteration approach to study the influence of a transverse magnetic field on the space charge limited bipolar flow in a planar vacuum diode. The results show that the limiting current density of the crossed-field vacuum diode may be approximately given by a complex function, including a 1D current density enhancement factor.
Article
Physics, Fluids & Plasmas
Jacob M. Halpern, Adam M. Darr, N. R. Sree Harsha, Allen L. Garner
Summary: Recent studies have extended the classical space-charge limited current (SCLC) solution to various geometries using variational calculus (VC), exploring solutions for non-planar diodes with different injection velocities.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
P. Glidic, O. Maillet, C. Piquard, A. Aassime, A. Cavanna, Y. Jin, U. Gennser, A. Anthore, F. Pierre
Summary: In fractional quantum Hall regime, we observe the unconventional behavior of exotic quasiparticles in electrical conduction and scattering. Unlike standard elastic scattering, electrical conduction no longer conserves the nature and number of quasiparticles. The experiment shows the emergence of a mechanism resembling Andreev reflection at a normal-superconductor interface, which advances our understanding of fractional quasiparticles.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Minhee Kim, Se-Hee Lee
Summary: The study analyzed the impact of accumulated space charge on electric field distortion and breakdown strength in polymeric insulators in an HVDC environment using a bipolar charge transport model. It was found that temperature gradient accelerates the reduction of breakdown strength, and internal energy imbalance caused by polarity-reversal voltage significantly decreases breakdown strength.
Article
Physics, Condensed Matter
S. M. T. Kazmi, Z. Zahoor, N. T. Yusra, M. H. Bhatti, M. F. Afsar, F. Sher, Haroon-ur Rashid, M. A. Rafiq
Summary: We investigated the electron transport properties of cobalt sulphide Schottky diodes with Au and Ag metal contacts. The diode parameters, such as ideality factor, barrier height, and Richardson coefficient, were calculated for Au/CoS2 and Ag/CoS2 diodes based on their temperature dependent IV characteristics. The barrier height increased with temperature for both devices, but the ideality factor showed different trends. The modified Richardson coefficient values were determined to be 244.20 Acm-2K-2 and 348.20 Acm-2K-2 for Au/CoS2 and Ag/CoS2 diodes, respectively. In the Au/CoS2 diode, a Space Charge Limited Current (SCLC) with an exponential trap distribution was observed at high voltages. The trap density and characteristic temperature associated with these traps were found to be 2.47 x 1014 cm-3 and 141 K, respectively.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Andre Erpenbeck, Yaling Ke, Uri Peskin, Michael Thoss
Summary: This publication focuses on the current-induced changes in molecular conductance, revealing that molecular junctions that exhibit a decrease in conductance upon dissociation are more stable. The study also identifies characteristic signatures in the current of breaking junctions and their relationship with properties of the leads.
Article
Engineering, Electrical & Electronic
V. F. Guedes, K. Z. Nobrega, R. Ramos
Summary: This paper demonstrates the application of the Lambert-Tsallis Wq function in solving problems related to different models of SCLC. It provides useful mathematical tools for device engineers studying charge transport in microelectronic and nanoelectronic devices.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Materials Science, Multidisciplinary
Jiasheng Ru, Daomin Min, Michael Lanagan, Shengtao Li, George Chen
Summary: This study presents a novel method for controlling the morphology of multilayer PI nanocomposites, achieving high breakdown field and discharged energy density in high temperature applications. The sandwich-structured PI nanocomposites show promise for energy storage capacitors, especially in extreme temperature environments.
MATERIALS & DESIGN
(2021)
Article
Physics, Applied
Xiaoping Wang, Shusai Zheng, Zhen Li, Shaoming Pan, Weibo Fan, Daomin Min, Shengtao Li
Summary: This paper investigates the surface flashover properties on the vacuum-dielectric interface irradiated by electrons. A 'three-segment' curve is discovered, showing the trend of increasing, decreasing, and stabilizing surface flashover voltage of polyimide with increasing electrode gap distance. Based on the simulation of electron trajectories, a model combining the effects of both kinetic and deposited electrons on surface flashover is proposed. This provides guidance for improving surface flashover voltage during electron irradiation.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Multidisciplinary Sciences
Kunming Shi, Bin Chai, Haiyang Zou, Daomin Min, Shengtao Li, Pingkai Jiang, Xingyi Huang
Summary: This study investigates the contact electrification and charge dynamics on a typical tribomaterial using in situ methods. The results show that the number of transferred electrons increas with contact force/area and tends to reach saturation under increased friction cycles. The incorporation of high permittivity BaTiO3 nanoparticles enhances the capacitance and electron trapping capability of the nanocomposites, improving the output performance of triboelectric devices.
Article
Engineering, Multidisciplinary
Minzun Ji, Daomin Min, Qingzhou Wu, Wenfeng Liu, Shengtao Li, Shaorui Qin, Shenglong Zhu
Summary: This article investigates the scale and electrical conduction properties of the interfacial regions in electrical insulating polymer nanocomposites. Through simulation and experimentation, it is found that the ordered and tightly aggregated structure induced by the bound effect of nanofillers results in interfacial regions with low conductivity.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Physics, Applied
Daomin Min, Minzun Ji, Ziwei Gao, Zhuoli Cai, Qingzhou Wu, Jie Liu, Shengtao Li, Wenfeng Liu
Summary: Polymer dielectric capacitors are commonly used for high-power-density energy storage, but their energy storage density is low and they cannot withstand high temperatures or achieve high energy density. To improve these aspects, a unified model is needed to study the factors that affect energy storage performance. The bipolar charge transport (BCT) model is used to establish a comprehensive model that considers charge injections, carrier migration, trapping effects, and energy damage. The model accurately predicts breakdown strengths, discharged energy densities, and charge-discharge efficiencies for different materials and temperatures. It reveals that carrier injection and transport are crucial for determining the conductivity, breakdown, and energy storage of linear dielectrics. Coating a layer of SiO2 on BOPP film enhances breakdown strength and reduces heat and distortion, while reducing charge injection and space charge accumulation improves energy density and charge-discharge efficiency.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Polymer Science
Zhijie Yang, Dong Yue, Yuanhang Yao, Jialong Li, Qingguo Chi, Qingguo Chen, Daomin Min, Yu Feng
Summary: This paper reviews the research progress of all-organic polymer dielectrics and emphasizes strategies to enhance both dielectric and energy storage performance. By analyzing the effects of blending, filling, and multilayer structures on all-organic polymer dielectrics, the energy storage applications and prospects of this material are summarized.
Article
Physics, Applied
Zhen Li, Yongsen Han, Ji Liu, Daomin Min, Shengtao Li
Summary: In this study, the temperature-dependent direct current (DC) breakdown mechanisms of epoxy resin (EP)/TiO2 nanocomposites were investigated. The incorporation of nanoparticles reduced space charge accumulation and electric field distortion, while an increase in temperature accelerated space charge accumulation, electric field distortion, and molecular displacement. A DC breakdown simulation model was established to further explore the influence of carrier traps and molecular chain dynamics on temperature-dependent breakdown. The calculated results showed good agreement with experimental data, indicating that the temperature-dependent DC breakdown mechanisms are dominated by the synergistic effects of carrier traps and segment chain dynamics. Furthermore, a transition from segment chain to backbone dynamics was discovered near the glass-transition temperature for DC breakdown of EP/TiO2 nanocomposites.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Fluids & Plasmas
Shaoming Pan, Xiaoping Wang, Daomin Min, Dajian Li, Xiajin Rao, Yi Su, Jian Zhao, Shengtao Li
Summary: This article investigates the effects of negative surface charge on surface flashover using the particle tracking method. The results show that negative surface charge inhibits initial electron emission and flashover initiation, and hinders the multiplication of secondary electrons and flashover development.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Zhaoliang Xing, Chong Zhang, Mengyao Han, Ziwei Gao, Qingzhou Wu, Daomin Min
Summary: This study investigates the breakdown strength of PE nanocomposites by considering the effects of factors such as space charges, electron energy, and molecular chains. The simulation results suggest that the combination of trapping effect and binding effect of molecular chains significantly improves the breakdown electric field of the material.
APPLIED SCIENCES-BASEL
(2022)
Article
Polymer Science
Xiaodi Dong, Baoquan Wan, Yang Feng, Daomin Min, Ming-Sheng Zheng, Haiping Xu, Zhi-Min Dang, George Chen, Jun-Wei Zha
Summary: This study successfully synthesized all-organic polyimide (PI) films with ultra-low permittivity and high hydrophobicity by introducing a fluoroelastomer (FEM). The impact of the fluoroelastomer on the dielectric properties was studied through molecular dynamics simulations and practical tests.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Chemistry, Physical
Yuanwei Zhu, Haopeng Chen, Yu Chen, Guanghao Qu, Guanghao Lu, Daomin Min, Yongjie Nie, Shengtao Li
Summary: This study reveals that surface oxidation-dependent space-charge accumulation can effectively enhance the breakdown and flashover performances of polymeric insulating materials. The functions of surface oxidation on the interfacial barrier of LDPE were investigated through quantitative analysis of space-charge distributions and electric field distortion. The proposed mechanism of surface modification on space-charge behaviors provides guidance for selecting appropriate methods to modify space-charge accumulation and improve the insulating performance of polymeric films for high-voltage applications.
Article
Chemistry, Physical
Minzun Ji, Daomin Min, Yuwei Li, Lingyu Yang, Qingzhou Wu, Wenfeng Liu, Shengtao Li
Summary: Researchers have constructed sandwich-structured PI/BaTiO3 nanocomposites using in-situ synthesis and solution casting techniques, achieving an energy density of 7.44 J/cm3 while maintaining good charge-discharge efficiency. The organic/inorganic interfacial polarization and interlayer polarization significantly increase the dielectric constant. The sandwich structure redistributes the electric field and mitigates the electric field concentration, while the outer insulation layer blocks high current and heat breakdown paths. This work provides a new paradigm for exploring polyimide nanocomposites with enhanced energy density through a combination of experiments and simulations.
MATERIALS TODAY ENERGY
(2023)
Article
Polymer Science
Zhen Li, He Gao, Longfei Zhang, Ji Liu, Huan Niu, Mingru Li, Daomin Min, Shengtao Li
Summary: This study investigates the molecular dynamics and macro-dielectric performances of epoxy nanocomposites. It is found that EP/TiO2 nanocomposites with optimized filler content exhibit improved mechanical, thermal and dielectric properties. The DC breakdown strength of the nanocomposites initially increases and then decreases with temperature, while also significantly decreasing overall.
Article
Engineering, Electrical & Electronic
Poxin Wang, Daomin Min, Xiaofan Song, Ziwei Gao, Yutao Hao, Shihang Wang, Wenfeng Liu
Summary: This research constructs an energy storage and release model considering the charge trapping effects and simulates the high-temperature energy storage properties of polyimide nanocomposite dielectrics. The results show that increasing the charge injection barrier, deep trap energy, and deep trap density can effectively improve the discharged energy densities and energy efficiencies of dielectric capacitors. This study provides theoretical and model support for enhancing the high-temperature energy storage performance of nanocomposites.
IET NANODIELECTRICS
(2023)
Article
Engineering, Electrical & Electronic
Poxin Wang, Daomin Min, Xiaofan Song, Yuanshuo Zhang, Lingyu Yang, Shihang Wang, Shengtao Li
Summary: Linear polymer dielectrics have been widely used in high-energy density capacitors due to their high breakdown strength and lightweight, but their low-energy storage density limits their practical application. By constructing an energy storage and energy release model, the impact of charge hopping barrier and average hopping distance on the energy storage performance of polyetherimide nanocomposites (PEI PNCs) was simulated and analyzed. The findings provide theoretical and model support for insulation design and performance improvement of nanocomposite dielectrics.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)