Pub Date : 2024-09-15DOI: 10.35848/1882-0786/ad756e
Man Peng, Tianyu Xiang, Tao Lei and Hong Xu
A double M-shaped metasurface is proposed and produced to realize a high Q-factor resonance at 13 GHz. The numerical and experimental results show that the high Q excitation of the structure is caused by the strong toroidal dipole. The novel toroidal metasurface can be a refractive index sensor with a high sensitivity of 3.2 GHzRIU−1. In addition, the double layer metasurface can achieve frequency selection with a bandwidth of 0.27 GHz. The proposed metasurface further extends the application of toroidal dipole in the field of sensing, frequency selective surface and so on.
{"title":"Sensing and frequency selecting with toroidal resonance in metasurface","authors":"Man Peng, Tianyu Xiang, Tao Lei and Hong Xu","doi":"10.35848/1882-0786/ad756e","DOIUrl":"https://doi.org/10.35848/1882-0786/ad756e","url":null,"abstract":"A double M-shaped metasurface is proposed and produced to realize a high Q-factor resonance at 13 GHz. The numerical and experimental results show that the high Q excitation of the structure is caused by the strong toroidal dipole. The novel toroidal metasurface can be a refractive index sensor with a high sensitivity of 3.2 GHzRIU−1. In addition, the double layer metasurface can achieve frequency selection with a bandwidth of 0.27 GHz. The proposed metasurface further extends the application of toroidal dipole in the field of sensing, frequency selective surface and so on.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"33 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.35848/1882-0786/ad7667
Inho Seong, Sijun Kim, Woobeen Lee, Youngseok Lee, Chulhee Cho, Wonnyoung Jeong, Minsu Choi, Byeongyeop Choi, Huichan Seo, Sangheon Song and Shinjae You
A global model (GM) assumes ion energy ( ) on the electrode equals the time-averaged sheath voltage ( ). However, using particle-in-cell simulation, we found that differs from We propose a unified global model (UGM) that calculates and collisional energy losses of ions by employing plasma circuit and sheath models, accompanied by a voltage and current sensor. We compared the results of the UGM with the experimental measurements and the results revealed that UGM is closer to the experiment than GM. UGM shows a linear relationship with the experiment, indicating that the UGM is applicable for plasma monitoring.
{"title":"A unified global model accompanied with a voltage and current sensor for low-pressure capacitively coupled RF discharge","authors":"Inho Seong, Sijun Kim, Woobeen Lee, Youngseok Lee, Chulhee Cho, Wonnyoung Jeong, Minsu Choi, Byeongyeop Choi, Huichan Seo, Sangheon Song and Shinjae You","doi":"10.35848/1882-0786/ad7667","DOIUrl":"https://doi.org/10.35848/1882-0786/ad7667","url":null,"abstract":"A global model (GM) assumes ion energy ( ) on the electrode equals the time-averaged sheath voltage ( ). However, using particle-in-cell simulation, we found that differs from We propose a unified global model (UGM) that calculates and collisional energy losses of ions by employing plasma circuit and sheath models, accompanied by a voltage and current sensor. We compared the results of the UGM with the experimental measurements and the results revealed that UGM is closer to the experiment than GM. UGM shows a linear relationship with the experiment, indicating that the UGM is applicable for plasma monitoring.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142267634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The degradation of an n++ GaN regrown ohmic contact in a MIS-HEMT device induced by ion beam etching (IBE) damages and relevant mechanisms have been studied. Abnormal I–V behaviors of the etched n++ GaN were observed by the transfer length method using a Ti/Al/Ni/Au stack as the contact metal, and it can be recovered with the assistance of post-metallization rapid thermal annealing. According to further analysis, we speculate that the degradation of the ohmic contact originates from the preferential loss of nitrogen by IBE, which boosts the oxygen incorporation and formation of an oxide layer isolating the contact metal from the n++ GaN.
我们研究了离子束蚀刻（IBE）损伤引起的 MIS-HEMT 器件中 n++ GaN 再生欧姆触点的退化及其相关机制。使用钛/铝/镍/金叠层作为接触金属，通过转移长度法观察到了蚀刻后 n++ GaN 的异常 I-V 行为。根据进一步的分析，我们推测欧姆接触的退化源于 IBE 优先损失氮，从而促进了氧的掺入并形成了氧化层，将接触金属与 n++ GaN 隔离开来。
{"title":"Degradation mechanism of degenerate n-GaN ohmic contact induced by ion beam etching damage","authors":"Xinkun Zhang, Haoran Qie, Yu Zhou, Yaozong Zhong, Jianxun Liu, Quan Dai, Qian Li, Xiaoning Zhan, Xiaolu Guo, Xin Chen, Qian Sun, Hui Yang","doi":"10.35848/1882-0786/ad7349","DOIUrl":"https://doi.org/10.35848/1882-0786/ad7349","url":null,"abstract":"The degradation of an n<sup>++</sup> GaN regrown ohmic contact in a MIS-HEMT device induced by ion beam etching (IBE) damages and relevant mechanisms have been studied. Abnormal <italic toggle=\"yes\">I–V</italic> behaviors of the etched n<sup>++</sup> GaN were observed by the transfer length method using a Ti/Al/Ni/Au stack as the contact metal, and it can be recovered with the assistance of post-metallization rapid thermal annealing. According to further analysis, we speculate that the degradation of the ohmic contact originates from the preferential loss of nitrogen by IBE, which boosts the oxygen incorporation and formation of an oxide layer isolating the contact metal from the n<sup>++</sup> GaN.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"13 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.35848/1882-0786/ad6fe9
Maki Shimizu, Koki Sugimoto and Yasuto Hijikata
In this study, the Seebeck coefficient of a single-walled carbon nanotube (SWCNT) was evaluated using a nitrogen vacancy center in nanodiamonds as a thermometer. A temperature gradient was established across the SWCNT, and the temperatures of the nanodiamonds on the electrodes, along with the electromotive force between these electrodes, were measured. The Seebeck coefficient for a metallic SWCNT was determined to be 14.0 ± 1.1 μV K−1, which is consistent with results reported in previous studies. This methodology offers a promising approach for evaluating the thermoelectric properties of various nanomaterials.
{"title":"Thermoelectric measurements of nanomaterials by nanodiamond quantum thermometry","authors":"Maki Shimizu, Koki Sugimoto and Yasuto Hijikata","doi":"10.35848/1882-0786/ad6fe9","DOIUrl":"https://doi.org/10.35848/1882-0786/ad6fe9","url":null,"abstract":"In this study, the Seebeck coefficient of a single-walled carbon nanotube (SWCNT) was evaluated using a nitrogen vacancy center in nanodiamonds as a thermometer. A temperature gradient was established across the SWCNT, and the temperatures of the nanodiamonds on the electrodes, along with the electromotive force between these electrodes, were measured. The Seebeck coefficient for a metallic SWCNT was determined to be 14.0 ± 1.1 μV K−1, which is consistent with results reported in previous studies. This methodology offers a promising approach for evaluating the thermoelectric properties of various nanomaterials.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"14 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.35848/1882-0786/ad7456
Ryo Yamada, Motomasa Nakagawa, Shotaro Hirooka, Hirokazu Tada
Physical reservoir computing (PRC) with visible-light signals was demonstrated using dye-sensitized solar cells. The short-term memory required for PRC was confirmed using light pulse inputs. Waveform learning was demonstrated for nonlinear autoregressive moving-average time series level 2 (NARMA2) signals with normalized mean square error of 0.027. The relatively slow (milliseconds to seconds) and complex charge transfer dynamics in the TiO2 porous layer with redox reactions in the solution phase provided the characteristics required for PRC.
{"title":"Physical reservoir computing with visible-light signals using dye-sensitized solar cells","authors":"Ryo Yamada, Motomasa Nakagawa, Shotaro Hirooka, Hirokazu Tada","doi":"10.35848/1882-0786/ad7456","DOIUrl":"https://doi.org/10.35848/1882-0786/ad7456","url":null,"abstract":"Physical reservoir computing (PRC) with visible-light signals was demonstrated using dye-sensitized solar cells. The short-term memory required for PRC was confirmed using light pulse inputs. Waveform learning was demonstrated for nonlinear autoregressive moving-average time series level 2 (NARMA2) signals with normalized mean square error of 0.027. The relatively slow (milliseconds to seconds) and complex charge transfer dynamics in the TiO<sub>2</sub> porous layer with redox reactions in the solution phase provided the characteristics required for PRC.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"101 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-02DOI: 10.35848/1882-0786/ad708d
Masahiro Morimoto, Hikaru Nagahama, Shigeki Naka
Organic light-emitting diodes (OLEDs) that produce exciplexes in a bilayer are device structures that can dramatically reduce the turn-on voltage. In this study, we report that this device structure contributes to an impressive improvement in operating lifetime. The lifetime of our OLED is 200 times longer than that of conventional OLEDs, and the voltage does not change after 100 h of operation. The reason for the stable driving voltage is no carrier accumulation inside the device at all by using a displacement current measurement. Analyzing the carrier dynamics in this work will provide a comprehensive solution for OLED degradation.
{"title":"Stable driving voltage in exciplex-type OLEDs with a bilayer interface","authors":"Masahiro Morimoto, Hikaru Nagahama, Shigeki Naka","doi":"10.35848/1882-0786/ad708d","DOIUrl":"https://doi.org/10.35848/1882-0786/ad708d","url":null,"abstract":"Organic light-emitting diodes (OLEDs) that produce exciplexes in a bilayer are device structures that can dramatically reduce the turn-on voltage. In this study, we report that this device structure contributes to an impressive improvement in operating lifetime. The lifetime of our OLED is 200 times longer than that of conventional OLEDs, and the voltage does not change after 100 h of operation. The reason for the stable driving voltage is no carrier accumulation inside the device at all by using a displacement current measurement. Analyzing the carrier dynamics in this work will provide a comprehensive solution for OLED degradation.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"3 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.35848/1882-0786/ad6db6
Hirokazu Fujiwara, Cédric Bareille, Mario Okawa, Shik Shin, Toshiyuki Taniuchi
The rapid evolution of lithography technology necessitates faster pattern inspection methods. Here, we propose the use of laser-based photoemission electron microscopy (laser-PEEM) for high-throughput observation of latent images on an electron beam resist. We revealed that this technique can visualize latent images as chemical contrasts, and estimated the throughput millions of times higher than those of an atomic force microscope. Moreover, we estimated that throughput tens of thousands of times higher than a single-beam scanning electron microscope is achievable for post-developed resist patterns. This breakthrough highlights the potential of laser-PEEM to revolutionize a high-throughput lithographic pattern inspection in semiconductor manufacturing.
{"title":"High throughput observation of latent images on resist using laser-based photoemission electron microscopy","authors":"Hirokazu Fujiwara, Cédric Bareille, Mario Okawa, Shik Shin, Toshiyuki Taniuchi","doi":"10.35848/1882-0786/ad6db6","DOIUrl":"https://doi.org/10.35848/1882-0786/ad6db6","url":null,"abstract":"The rapid evolution of lithography technology necessitates faster pattern inspection methods. Here, we propose the use of laser-based photoemission electron microscopy (laser-PEEM) for high-throughput observation of latent images on an electron beam resist. We revealed that this technique can visualize latent images as chemical contrasts, and estimated the throughput millions of times higher than those of an atomic force microscope. Moreover, we estimated that throughput tens of thousands of times higher than a single-beam scanning electron microscope is achievable for post-developed resist patterns. This breakthrough highlights the potential of laser-PEEM to revolutionize a high-throughput lithographic pattern inspection in semiconductor manufacturing.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"73 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.35848/1882-0786/ad6ee7
Chengwen Wo, Ting Zhang, Li Sun, Xiaojun Liu
Utilizing the self-collimation effect in two-dimensional (2D) sonic crystals (SCs), we have proposed an acoustic notch filter which is composed of two perfect mirrors and a beam splitter. Numerical simulation shows that by properly designing the inside structure of the 2D SC, the self-collimated acoustic waves with a desired frequency can be trapped between the two mirrors, realizing the notch filtering function. Moreover, the frequency and bandwidth of the notch filter can be arbitrarily adjusted by changing the parameters of the internel structure, in a considerably broad band. Potential applications include acoustic communication and acoustic signal processing, especially for underwater circumstances.
{"title":"Acoustic notch filter based on self-collimation sonic crystals","authors":"Chengwen Wo, Ting Zhang, Li Sun, Xiaojun Liu","doi":"10.35848/1882-0786/ad6ee7","DOIUrl":"https://doi.org/10.35848/1882-0786/ad6ee7","url":null,"abstract":"Utilizing the self-collimation effect in two-dimensional (2D) sonic crystals (SCs), we have proposed an acoustic notch filter which is composed of two perfect mirrors and a beam splitter. Numerical simulation shows that by properly designing the inside structure of the 2D SC, the self-collimated acoustic waves with a desired frequency can be trapped between the two mirrors, realizing the notch filtering function. Moreover, the frequency and bandwidth of the notch filter can be arbitrarily adjusted by changing the parameters of the internel structure, in a considerably broad band. Potential applications include acoustic communication and acoustic signal processing, especially for underwater circumstances.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"27 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study describes high-power and high-efficiency W-band InAlGaN/AlN/GaN high-electron-mobility transistors (HEMTs) for future sub-terahertz wireless communications. A low-thermal-budget selective-area growth (SAG) process was developed to obtain low contact resistance with low trap states. Transmission lines and substrate structures were optimized to obtain high-thermal conductivity and low substrate resonance. Consequently, a high output power of 28.7 dBm (742 mW), output power density of 4.6 W mm−1, and power-added efficiency (PAE) of 28.0% were achieved with pre-matched InAlGaN/AlN/GaN HEMTs at 90 GHz, which were superior combination of output power and PAE compared to the conventional high-temperature SAG process.
本研究介绍了用于未来亚太赫兹无线通信的高功率、高效率 W 波段 InAlGaN/AlN/GaN 高电子迁移率晶体管（HEMT）。我们开发了一种低热预算选择性区域生长（SAG）工艺，以获得低接触电阻和低阱态。对传输线和衬底结构进行了优化，以获得高热导率和低衬底谐振。因此，与传统的高温 SAG 工艺相比，预匹配 InAlGaN/AlN/GaN HEMT 在 90 GHz 频率下实现了 28.7 dBm (742 mW) 的高输出功率、4.6 W mm-1 的输出功率密度和 28.0% 的功率附加效率 (PAE)。
{"title":"High-power and efficiency W-band InAlGaN/AlN/GaN high-electron-mobility transistors for future high-capacity wireless communications","authors":"Yusuke Kumazaki, Shiro Ozaki, Yasuhiro Nakasha, Naoya Okamoto, Atsushi Yamada, Toshihiro Ohki","doi":"10.35848/1882-0786/ad68c2","DOIUrl":"https://doi.org/10.35848/1882-0786/ad68c2","url":null,"abstract":"This study describes high-power and high-efficiency W-band InAlGaN/AlN/GaN high-electron-mobility transistors (HEMTs) for future sub-terahertz wireless communications. A low-thermal-budget selective-area growth (SAG) process was developed to obtain low contact resistance with low trap states. Transmission lines and substrate structures were optimized to obtain high-thermal conductivity and low substrate resonance. Consequently, a high output power of 28.7 dBm (742 mW), output power density of 4.6 W mm<sup>−1</sup>, and power-added efficiency (PAE) of 28.0% were achieved with pre-matched InAlGaN/AlN/GaN HEMTs at 90 GHz, which were superior combination of output power and PAE compared to the conventional high-temperature SAG process.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"35 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have proposed highly efficient microcavity wavelength conversion devices that do not utilize the birefringence or ferroelectricity of crystals. In this study, we utilized a low-birefringence paraelectric SrB4O7 crystal with significant potential for wavelength conversion and high transparency down to 130 nm and succeeded in achieving 199 nm vacuum-ultraviolet second harmonic generation (SHG) with a picosecond laser. The wavelength of 199 nm is shorter than the theoretical minimum for SHG in BaB2O4 of 205 nm. Our device could be a practical vacuum-ultraviolet SHG device, enabling significantly smaller and more efficient vacuum-ultraviolet laser sources compared to conventional systems.
{"title":"199 nm vacuum-ultraviolet second harmonic generation from SrB4O7 vertical microcavity pumped with picosecond laser","authors":"Tomoaki Nambu, Masashi Yoshimura, Yusuke Mori, Yasufumi Fujiwara, Ryota Ishii, Yoichi Kawakami, Masahiro Uemukai, Tomoyuki Tanikawa, Ryuji Katayama","doi":"10.35848/1882-0786/ad69fe","DOIUrl":"https://doi.org/10.35848/1882-0786/ad69fe","url":null,"abstract":"We have proposed highly efficient microcavity wavelength conversion devices that do not utilize the birefringence or ferroelectricity of crystals. In this study, we utilized a low-birefringence paraelectric SrB<sub>4</sub>O<sub>7</sub> crystal with significant potential for wavelength conversion and high transparency down to 130 nm and succeeded in achieving 199 nm vacuum-ultraviolet second harmonic generation (SHG) with a picosecond laser. The wavelength of 199 nm is shorter than the theoretical minimum for SHG in BaB<sub>2</sub>O<sub>4</sub> of 205 nm. Our device could be a practical vacuum-ultraviolet SHG device, enabling significantly smaller and more efficient vacuum-ultraviolet laser sources compared to conventional systems.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"27 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142198239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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