In this letter, a novel power synthesis scheme is proposed for high-power terahertz (THz) traveling-wave tube (TWT), which features a quadruple folded groove-guide (Q-FGG) slow wave structure (SWS) and a power synthesis circuit. Numerical simulations validate the high-frequency characteristics of Q-FGG-SWS. Particle-In-Cell (PIC) simulations predict that, driven by four 125mA electron beams at 28.4kV, the Q-FGG-TWT is expected to achieve possibility of output power of approximately 177.3W at 316GHz. The Q-FGG-SWSs were fabricated using high-precision computer numerical control (CNC) milling technology. The dispersion characteristics of Q-FGG-SWS and transmission characteristics of the Q-FGG-SWSs based on the compact multi-stage groove-T coupler were experimentally verified. Therefore, the Q-FGG-SWS with a compact power synthesis circuit offers a promising approach for enhancing the power output of THz-TWTs.
{"title":"Quadruple Folded Groove-Guide Slow Wave Structure With Power Synthesis Circuit for Terahertz TWT","authors":"Jingrui Duan;Zhigang Lu;Peng Gao;Zechuan Wang;Jingyu Guo;Yang Dong;Yuan Zheng;Zhanliang Wang;Shaomeng Wang;Huarong Gong;Yubin Gong","doi":"10.1109/LED.2024.3515646","DOIUrl":"https://doi.org/10.1109/LED.2024.3515646","url":null,"abstract":"In this letter, a novel power synthesis scheme is proposed for high-power terahertz (THz) traveling-wave tube (TWT), which features a quadruple folded groove-guide (Q-FGG) slow wave structure (SWS) and a power synthesis circuit. Numerical simulations validate the high-frequency characteristics of Q-FGG-SWS. Particle-In-Cell (PIC) simulations predict that, driven by four 125mA electron beams at 28.4kV, the Q-FGG-TWT is expected to achieve possibility of output power of approximately 177.3W at 316GHz. The Q-FGG-SWSs were fabricated using high-precision computer numerical control (CNC) milling technology. The dispersion characteristics of Q-FGG-SWS and transmission characteristics of the Q-FGG-SWSs based on the compact multi-stage groove-T coupler were experimentally verified. Therefore, the Q-FGG-SWS with a compact power synthesis circuit offers a promising approach for enhancing the power output of THz-TWTs.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"302-305"},"PeriodicalIF":4.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-11DOI: 10.1109/LED.2024.3514783
Hao Sun;Yu Heng Deng;Qing He Wang;P. T. Lai
Pentacene organic thin-film transistors (OTFTs) with HfLaON high-k gate dielectric have been fabricated using various gate-electrode materials, including different metals (Al, Au, Cu, Cr, Ti and Pt), as well as n-type highly-doped Si (n+-Si) and lowly-doped Si (n-Si). The OTFTs with metal gates exhibit significantly higher channel-carrier mobility (4.65 cm2V-1s-1 to 9.21 cm2V-1s-1) than their counterparts with n+-Si gate (1.52 cm2V-1s-1) and n-Si gate (0.12 cm2V-1s-1). Furthermore, among the metal-gate samples, despite having similar pentacene grain size and gate-dielectric surface roughness, the Ti-gate sample obtains the highest channel-carrier mobility of 9.21 cm2V-1s-1. This should be attributed to its highest gate plasmon energy resulting from both high electron concentration and low effective electron mass in its gate electrode, thus producing the strongest gate screening effect on the remote phonon scattering (RPS) arising from the thermal vibration of the high-k gate dielectric. In summary, metals with high plasmon energy (e.g. Ti, Al) should be chosen as the gate electrode material to achieve high channel-carrier mobility in TFT.
{"title":"Choice of Metal as Gate Electrode of Thin-Film Transistor With High-k Gate Dielectric","authors":"Hao Sun;Yu Heng Deng;Qing He Wang;P. T. Lai","doi":"10.1109/LED.2024.3514783","DOIUrl":"https://doi.org/10.1109/LED.2024.3514783","url":null,"abstract":"Pentacene organic thin-film transistors (OTFTs) with HfLaON high-k gate dielectric have been fabricated using various gate-electrode materials, including different metals (Al, Au, Cu, Cr, Ti and Pt), as well as n-type highly-doped Si (n+-Si) and lowly-doped Si (n-Si). The OTFTs with metal gates exhibit significantly higher channel-carrier mobility (4.65 cm2V-1s-1 to 9.21 cm2V-1s-1) than their counterparts with n+-Si gate (1.52 cm2V-1s-1) and n-Si gate (0.12 cm2V-1s-1). Furthermore, among the metal-gate samples, despite having similar pentacene grain size and gate-dielectric surface roughness, the Ti-gate sample obtains the highest channel-carrier mobility of 9.21 cm2V-1s-1. This should be attributed to its highest gate plasmon energy resulting from both high electron concentration and low effective electron mass in its gate electrode, thus producing the strongest gate screening effect on the remote phonon scattering (RPS) arising from the thermal vibration of the high-k gate dielectric. In summary, metals with high plasmon energy (e.g. Ti, Al) should be chosen as the gate electrode material to achieve high channel-carrier mobility in TFT.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"286-289"},"PeriodicalIF":4.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-11DOI: 10.1109/LED.2024.3515147
Jiajia Jian;Xihui Yuan;Zheng Chai;Xue Zhou;Yongjie Luo;Yingtong He;Xin Yue;Jian Fu Zhang;Weidong Zhang;Tai Min
The generation of high quality bipolar random signal for unconventional computing and artificial neural networks remains challenging. In this study, we proposed a new method to generate bipolar random signals using two industrial-viable magnetic tunnel junctions (MTJs) operated solely by electrical operations compatible to the conventional memory program/read circuits. The bipolar random signals demonstrate excellent randomness and this method shows satisfying controllability over the average dwell times (ADTs), with good adjustability in bit generation speed and power consumption. This study provides a new practical hardware solution to the generation of high-quality random signals in the post-Moore era.
{"title":"Bipolar Random Signal Generation With Electrical Operation Based on Two Magnetic Tunnel Junctions","authors":"Jiajia Jian;Xihui Yuan;Zheng Chai;Xue Zhou;Yongjie Luo;Yingtong He;Xin Yue;Jian Fu Zhang;Weidong Zhang;Tai Min","doi":"10.1109/LED.2024.3515147","DOIUrl":"https://doi.org/10.1109/LED.2024.3515147","url":null,"abstract":"The generation of high quality bipolar random signal for unconventional computing and artificial neural networks remains challenging. In this study, we proposed a new method to generate bipolar random signals using two industrial-viable magnetic tunnel junctions (MTJs) operated solely by electrical operations compatible to the conventional memory program/read circuits. The bipolar random signals demonstrate excellent randomness and this method shows satisfying controllability over the average dwell times (ADTs), with good adjustability in bit generation speed and power consumption. This study provides a new practical hardware solution to the generation of high-quality random signals in the post-Moore era.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"171-174"},"PeriodicalIF":4.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10793412","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this letter, a unique region dependence of positive and negative bias stress (PBS/NBS) stabilities is investigated in InGaZnO (IGZO) thin-film transistors (TFTs). Based on the floating channel effect, the electric field of the channel region is solely modified with remained source and drain (S/D) region potential by applying S/D biases and grounded gate compared to traditional PBS and NBS tests, so that the role of different regions in IGZO is decoupled. A new degradation model is built to elucidate the NBS issues. It provides more direct evidence to indicate that the migration of defects in S/D region, rather than channel region, dominates NBS responses in IGZO TFTs. The effect of proposed region dependence model on PBS stability is discussed as well. This work unveils a stability mechanism in sub-$mu $ m IGZO TFTs, providing new insights into achieving reliable devices for 3D DRAM.
{"title":"Unveiling the Unique Region Dependence of Bias Stability in Sub-μm IGZO TFTs Using Floating Channel Effect for 3D DRAM","authors":"Yanyu Yang;Gangping Yan;Jie Luo;Yupeng Lu;Yunjiao Bao;Chuqiao Niu;Xueli Ma;Jinjuan Xiang;Gaobo Xu;Guilei Wang;Chao Zhao;Huaxiang Yin","doi":"10.1109/LED.2024.3515091","DOIUrl":"https://doi.org/10.1109/LED.2024.3515091","url":null,"abstract":"In this letter, a unique region dependence of positive and negative bias stress (PBS/NBS) stabilities is investigated in InGaZnO (IGZO) thin-film transistors (TFTs). Based on the floating channel effect, the electric field of the channel region is solely modified with remained source and drain (S/D) region potential by applying S/D biases and grounded gate compared to traditional PBS and NBS tests, so that the role of different regions in IGZO is decoupled. A new degradation model is built to elucidate the NBS issues. It provides more direct evidence to indicate that the migration of defects in S/D region, rather than channel region, dominates NBS responses in IGZO TFTs. The effect of proposed region dependence model on PBS stability is discussed as well. This work unveils a stability mechanism in sub-<inline-formula> <tex-math>$mu $ </tex-math></inline-formula>m IGZO TFTs, providing new insights into achieving reliable devices for 3D DRAM.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"290-293"},"PeriodicalIF":4.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this article, we experimentally propose a reverse-blocking (RB) p-GaN gate transistor with the Schottky-MIS cascode drain (CDT) for the significantly reduced forward voltage drop ${textit {V}}_{mathbf {F}}$ and ultralow reverse leakage current ${I}_{mathbf {textit {LEAK}}}$ . At forward bias, electron concentration at the Schottky-MIS cascode drain is higher than that at conventional p-GaN/Ohmic drain. When experiencing reverse bias, the Schottky-MIS cascode drain effectively protects the Schottky contact from the high reverse potential compared to Schottky drain. The fabricated Schottky-MIS CDT presents a superior ${V}_{mathbf {F}}$ - ${I}_{mathbf {textit {LEAK}}}$ relationship including a greatly reduced ${V}_{mathbf {F}}$ of 3.1V as well as an ultralow ${I}_{mathbf {textit {LEAK}}}$ of ${1}times {10} ^{-{8}}$ A/mm, together with a competitive reverse power figure-of-merit (FOM) of 120MW/cm2. These performances suggest that the proposed Schottky-MIS CDT can be a promising candidate for low-loss RB GaN power transistors and applications requiring a better ${V}_{mathbf {F}}$ - ${I} _{mathbf {textit {LEAK}}}$ trade-off.
{"title":"Schottky-MIS Cascode Drain Reverse-Blocking p-GaN Gate Transistor With Significantly Reduced Forward Drop and Ultralow Leakage Current","authors":"Fangzhou Wang;Changhong Gao;Guojian Ding;Cheng Yu;Xiaoliang Wang;Zhuocheng Wang;Xiaohui Wang;Qi Feng;Ping Yu;Xinghuan Chen;Yang Wang;Wanjun Chen;Haiqiang Jia;Hong Chen;Bo Zhang;Zeheng Wang","doi":"10.1109/LED.2024.3515211","DOIUrl":"https://doi.org/10.1109/LED.2024.3515211","url":null,"abstract":"In this article, we experimentally propose a reverse-blocking (RB) p-GaN gate transistor with the Schottky-MIS cascode drain (CDT) for the significantly reduced forward voltage drop <inline-formula> <tex-math>${textit {V}}_{mathbf {F}}$ </tex-math></inline-formula> and ultralow reverse leakage current <inline-formula> <tex-math>${I}_{mathbf {textit {LEAK}}}$ </tex-math></inline-formula>. At forward bias, electron concentration at the Schottky-MIS cascode drain is higher than that at conventional p-GaN/Ohmic drain. When experiencing reverse bias, the Schottky-MIS cascode drain effectively protects the Schottky contact from the high reverse potential compared to Schottky drain. The fabricated Schottky-MIS CDT presents a superior <inline-formula> <tex-math>${V}_{mathbf {F}}$ </tex-math></inline-formula> - <inline-formula> <tex-math>${I}_{mathbf {textit {LEAK}}}$ </tex-math></inline-formula> relationship including a greatly reduced <inline-formula> <tex-math>${V}_{mathbf {F}}$ </tex-math></inline-formula> of 3.1V as well as an ultralow <inline-formula> <tex-math>${I}_{mathbf {textit {LEAK}}}$ </tex-math></inline-formula> of <inline-formula> <tex-math>${1}times {10} ^{-{8}}$ </tex-math></inline-formula> A/mm, together with a competitive reverse power figure-of-merit (FOM) of 120MW/cm2. These performances suggest that the proposed Schottky-MIS CDT can be a promising candidate for low-loss RB GaN power transistors and applications requiring a better <inline-formula> <tex-math>${V}_{mathbf {F}}$ </tex-math></inline-formula> - <inline-formula> <tex-math>${I} _{mathbf {textit {LEAK}}}$ </tex-math></inline-formula> trade-off.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"131-134"},"PeriodicalIF":4.1,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With rapid advances in THz devices, the human exposure to THz waves increases, necessitating thorough safety assessment before commercialization. Despite the significance of frequencies such as 600 GHz in next-generation technologies, currently, no gyrotron is specifically designed for exposure experiments at such high frequencies. Therefore, we developed a 600-GHz continuous wave (CW) gyrotron with a Gaussian beam output to assess exposure to terahertz radiation. First experiment of this gyrotron was carried out. After axial alignment, a Gaussian-like beam with a frequency of 599.1 GHz was emitted, achieving continuous oscillation for 10 min with a power output of 2.4 W.
{"title":"First Experiment of a 600-GHz CW Gyrotron Developed as Light Source for EMF Exposure Assessment","authors":"Y. Tatematsu;Y. Yamaguchi;M. Fukunari;M. Hayakawa;R. Kai;Y. Kawai;R. Matoba;K. Sasaki;T. Shirotori;G. Suzuki;J. Tanaka;M. Mizuno;T. Nagaoka","doi":"10.1109/LED.2024.3513448","DOIUrl":"https://doi.org/10.1109/LED.2024.3513448","url":null,"abstract":"With rapid advances in THz devices, the human exposure to THz waves increases, necessitating thorough safety assessment before commercialization. Despite the significance of frequencies such as 600 GHz in next-generation technologies, currently, no gyrotron is specifically designed for exposure experiments at such high frequencies. Therefore, we developed a 600-GHz continuous wave (CW) gyrotron with a Gaussian beam output to assess exposure to terahertz radiation. First experiment of this gyrotron was carried out. After axial alignment, a Gaussian-like beam with a frequency of 599.1 GHz was emitted, achieving continuous oscillation for 10 min with a power output of 2.4 W.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"310-313"},"PeriodicalIF":4.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10786247","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/LED.2024.3513410
Junyan Zheng;Xingyu Liu;Yansong Yang
Piezoelectric MEMS resonator is one of the key components in acousto-optic modulators, and different types of acoustic resonators have been utilized to realize acousto-optic modulation. However, current acoustic resonators cannot support the high-frequency scenario as high-frequency acoustic waves are hard to propagate coupling with light waves for large modal overlap. To eliminate mechanical and optical losses from metal, this study introduces a novel structure featuring suspended electrodes above the suspended piezoelectric thin film. By utilizing metal-air-piezoelectric (MAP) thin film structures, these resonators enable the propagation of light waves into the acoustic resonator, thus facilitating acousto-optic interaction while minimizing light wave absorption by the metal. The fabrication process involves the removal of two sacrificial layers to suspend the stacked electrodes and piezoelectric film, resulting in the successful excitation of the antisymmetric Lamb waves (A-modes). The fabricated device demonstrates the A1 mode at 10.38 GHz, exhibiting an extracted ${K}_{textit {mat}}^{{2}}$ of 28% and an extracted ${Q}_{textit {MBVD}}$ of 380. Additionally, the A3 mode is achieved at 31 GHz, with a ${K}_{textit {mat}}^{{2}}$ of 5% and a ${Q}_{textit {MBVD}}$ of 280. Through further optimization and investigation, this innovative structure is expected to enable acousto-optic modulation at mmWave frequencies.
{"title":"Metal-Air-Piezoelectric (MAP) mmWave Resonator","authors":"Junyan Zheng;Xingyu Liu;Yansong Yang","doi":"10.1109/LED.2024.3513410","DOIUrl":"https://doi.org/10.1109/LED.2024.3513410","url":null,"abstract":"Piezoelectric MEMS resonator is one of the key components in acousto-optic modulators, and different types of acoustic resonators have been utilized to realize acousto-optic modulation. However, current acoustic resonators cannot support the high-frequency scenario as high-frequency acoustic waves are hard to propagate coupling with light waves for large modal overlap. To eliminate mechanical and optical losses from metal, this study introduces a novel structure featuring suspended electrodes above the suspended piezoelectric thin film. By utilizing metal-air-piezoelectric (MAP) thin film structures, these resonators enable the propagation of light waves into the acoustic resonator, thus facilitating acousto-optic interaction while minimizing light wave absorption by the metal. The fabrication process involves the removal of two sacrificial layers to suspend the stacked electrodes and piezoelectric film, resulting in the successful excitation of the antisymmetric Lamb waves (A-modes). The fabricated device demonstrates the A1 mode at 10.38 GHz, exhibiting an extracted <inline-formula> <tex-math>${K}_{textit {mat}}^{{2}}$ </tex-math></inline-formula> of 28% and an extracted <inline-formula> <tex-math>${Q}_{textit {MBVD}}$ </tex-math></inline-formula> of 380. Additionally, the A3 mode is achieved at 31 GHz, with a <inline-formula> <tex-math>${K}_{textit {mat}}^{{2}}$ </tex-math></inline-formula> of 5% and a <inline-formula> <tex-math>${Q}_{textit {MBVD}}$ </tex-math></inline-formula> of 280. Through further optimization and investigation, this innovative structure is expected to enable acousto-optic modulation at mmWave frequencies.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"167-170"},"PeriodicalIF":4.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/LED.2024.3513322
Xiaotian Tang;Zhongchen Ji;Qimeng Jiang;Sen Huang;Xinguo Gao;Ke Wei;Xinhua Wang;Xinyu Liu
A Hybrid-Source p-GaN gate Normally-OFF AlGaN/GaN HEMT is proposed and successfully fabricated, based on a decoupled double-channel structure. It mitigates the compatibility issue between the p-GaN gate and double-channel structures by decoupling the upper and lower channels through a Hybrid-Source structure. Thanks to the source-side Schottky connection to the lower channel, an extremely low reverse turn-ON voltage (-0.5 V) and a large forward threshold voltage (+3.2 V) are simultaneously achieved.
{"title":"Decoupled Double-Channel p-GaN Gate AlGaN/GaN HEMT Featuring Low Reverse Conduction Loss and High Forward Threshold Voltage","authors":"Xiaotian Tang;Zhongchen Ji;Qimeng Jiang;Sen Huang;Xinguo Gao;Ke Wei;Xinhua Wang;Xinyu Liu","doi":"10.1109/LED.2024.3513322","DOIUrl":"https://doi.org/10.1109/LED.2024.3513322","url":null,"abstract":"A Hybrid-Source p-GaN gate Normally-OFF AlGaN/GaN HEMT is proposed and successfully fabricated, based on a decoupled double-channel structure. It mitigates the compatibility issue between the p-GaN gate and double-channel structures by decoupling the upper and lower channels through a Hybrid-Source structure. Thanks to the source-side Schottky connection to the lower channel, an extremely low reverse turn-ON voltage (-0.5 V) and a large forward threshold voltage (+3.2 V) are simultaneously achieved.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"147-150"},"PeriodicalIF":4.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/LED.2024.3513417
Liang Chen;Wenliang Wang;Guoqiang Li
Flexible InGaN-based photodetectors have broad application prospects in wearable biometric monitoring and visible light communication (VLC). However, flexible InGaN-based visible light photodetectors (VLPDs) still face challenges of low responsivity due to poor material quality and low light absorption efficiency. This work demonstrates a high-performance flexible VLPD integrating a TiO2/SiO2 distributed Bragg reflector (DBR) mirror with an InGaN/GaN MQWs nanomembrane. The optical field density is significantly enhanced by introducing the DBR mirror, resulting in a 22% improvement in PD’s responsivity (68.6 mA/W@-1 V). The photoresponse time ($text {T} _{text {r}}$ /$text {T} _{text {f}}text {)}$ of PD are $24.4~mu $ s and $6.1~mu $ s, respectively. The −3 dB bandwidth of PD is 106.2 kHz. The flexible PD exhibits good stability over multiple bending cycles and long periods in the air. A real-time and precise VLC system link has been established based on high-performance flexible PDs, achieving a data rate of 9 Kbps. This research offers a strategic approach for designing high-performance flexible VLPDs towards VLC.
{"title":"High-Responsivity Flexible InGaN/GaN MQWs Nanomembrane Photodetectors With DBR Mirror Toward Visible Light Communication","authors":"Liang Chen;Wenliang Wang;Guoqiang Li","doi":"10.1109/LED.2024.3513417","DOIUrl":"https://doi.org/10.1109/LED.2024.3513417","url":null,"abstract":"Flexible InGaN-based photodetectors have broad application prospects in wearable biometric monitoring and visible light communication (VLC). However, flexible InGaN-based visible light photodetectors (VLPDs) still face challenges of low responsivity due to poor material quality and low light absorption efficiency. This work demonstrates a high-performance flexible VLPD integrating a TiO2/SiO2 distributed Bragg reflector (DBR) mirror with an InGaN/GaN MQWs nanomembrane. The optical field density is significantly enhanced by introducing the DBR mirror, resulting in a 22% improvement in PD’s responsivity (68.6 mA/W@-1 V). The photoresponse time (<inline-formula> <tex-math>$text {T} _{text {r}}$ </tex-math></inline-formula>/<inline-formula> <tex-math>$text {T} _{text {f}}text {)}$ </tex-math></inline-formula> of PD are <inline-formula> <tex-math>$24.4~mu $ </tex-math></inline-formula>s and <inline-formula> <tex-math>$6.1~mu $ </tex-math></inline-formula>s, respectively. The −3 dB bandwidth of PD is 106.2 kHz. The flexible PD exhibits good stability over multiple bending cycles and long periods in the air. A real-time and precise VLC system link has been established based on high-performance flexible PDs, achieving a data rate of 9 Kbps. This research offers a strategic approach for designing high-performance flexible VLPDs towards VLC.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"219-222"},"PeriodicalIF":4.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/LED.2024.3513954
Zhengren Yan;Pengqi Lu;Yuyan Chu;Tao Jiang;Jinyao Li;Wei Fang;Shikun He
Under the influence of an external magnetic field, the macrospin model predicts that the free layer of a magnetic tunnel junction (MTJ) exhibits a minimum energy barrier when the applied field is oriented at 45°. However, recent chip-scale experiments have yielded inconsistent results, indicating the limitations of current models in accurately predicting MRAM’s magnetic immunity. In this work, we present a domain wall motion-based model that provides novel insights. By employing the small-angle approximation and linearizing the domain wall energy under the influence of a transverse magnetic field, we have derived an analytical formula that well fits the experimental data of the perpendicular STT-MRAM. Our findings indicate a minimum switching barrier occurring at a special field angle (~60°), which could be manipulated by the field strength and the magnetic properties of device. The proposed model enables a more precise quantitative assessment of magnetic immunity at the chip level and offers valuable guidance for device optimization and shielding method development.
{"title":"Magnetic-Field Orientation Dependence of Thermal Stability in Perpendicular STT-MRAM","authors":"Zhengren Yan;Pengqi Lu;Yuyan Chu;Tao Jiang;Jinyao Li;Wei Fang;Shikun He","doi":"10.1109/LED.2024.3513954","DOIUrl":"https://doi.org/10.1109/LED.2024.3513954","url":null,"abstract":"Under the influence of an external magnetic field, the macrospin model predicts that the free layer of a magnetic tunnel junction (MTJ) exhibits a minimum energy barrier when the applied field is oriented at 45°. However, recent chip-scale experiments have yielded inconsistent results, indicating the limitations of current models in accurately predicting MRAM’s magnetic immunity. In this work, we present a domain wall motion-based model that provides novel insights. By employing the small-angle approximation and linearizing the domain wall energy under the influence of a transverse magnetic field, we have derived an analytical formula that well fits the experimental data of the perpendicular STT-MRAM. Our findings indicate a minimum switching barrier occurring at a special field angle (~60°), which could be manipulated by the field strength and the magnetic properties of device. The proposed model enables a more precise quantitative assessment of magnetic immunity at the chip level and offers valuable guidance for device optimization and shielding method development.","PeriodicalId":13198,"journal":{"name":"IEEE Electron Device Letters","volume":"46 2","pages":"191-194"},"PeriodicalIF":4.1,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10786880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143184525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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