{"title":"Rutile-type Ge x Sn1−x O2 alloy layers lattice-matched to TiO2 substrates for device applications","authors":"Hitoshi Takane, Takayoshi Oshima, Takayuki Harada, Kentaro Kaneko and Katsuhisa Tanaka","doi":"10.35848/1882-0786/ad15f3","DOIUrl":"https://doi.org/10.35848/1882-0786/ad15f3","url":null,"abstract":"We report the characterization and application of mist-CVD-grown rutile-structured GexSn1−xO2 (x = ∼0.53) films lattice-matched to isostructural TiO2(001) substrates. The grown surface was flat throughout the growth owing to the lattice-matching epitaxy. Additionally, the film was single-crystalline without misoriented domains and TEM-detectable threading dislocations due to the coherent heterointerface. Using the Ge0.49Sn0.51O2 film with a carrier density of 7.8 × 1018 cm−3 and a mobility of 24 cm2V−1s−1, lateral Schottky barrier diodes were fabricated with Pt anodes and Ti/Au cathodes. The diodes exhibited rectifying properties with a rectification ratio of 8.2 × 104 at ±5 V, showing the potential of GexSn1-xO2 as a practical semiconductor.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"72 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139084490","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}
Han Ye, Qin Han, Shuai Wang, Yimiao Chu, Yu Zheng and Liyan Geng
{"title":"High speed evanescent waveguide photodetector with a 100 GHz bandwidth","authors":"Han Ye, Qin Han, Shuai Wang, Yimiao Chu, Yu Zheng and Liyan Geng","doi":"10.35848/1882-0786/ad0e90","DOIUrl":"https://doi.org/10.35848/1882-0786/ad0e90","url":null,"abstract":"The upcoming beyond-5G and 6G ultra-high speed transmission networks have urged photonic transceivers to allow for higher bandwidth performance. In this work, an evanescent coupled high speed waveguide photodetector (PD) is fabricated and analyzed. Adopting a modified uni-traveling carrier structure, the PD exhibits a bandwidth of 100 GHz and a low dark current of 3 nA at −1.5 V. Numerical simulations show that the measured responsivity of 0.25 A W−1 is worsened by the inaccurate cleaving length of the coupling waveguide, and could potentially reach 0.688 A W−1 with anti-reflection film at the facet. The bandwidth is bound by high resistance and capacitance giving a transit-time limit as high as 310 GHz.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"135 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139071011","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}
{"title":"Wide-field imaging of the magnetization process in soft magnetic-thin film using diamond quantum sensors","authors":"Ryota Kitagawa, Teruo Kohashi, Takeyuki Tsuji, Shunsuke Nagata, Aoi Nakatsuka, Honami Nitta, Yota Takamura, Shigeki Nakagawa, Takayuki Iwasaki and Mutsuko Hatano","doi":"10.35848/1882-0786/ad1002","DOIUrl":"https://doi.org/10.35848/1882-0786/ad1002","url":null,"abstract":"The magnetization process of a soft magnetic CoFeB-SiO2 thin film was imaged using diamond quantum sensors with perfectly aligned nitrogen-vacancy centers along the [111] direction formed by CVD. Around the film edge, the easy and hard axes directions exhibited different responses to the external magnetic field, consistent with ones observed by magneto-optical Kerr effect microscopy. Moreover, quantum diamond imaging could observe discontinuous magnetization along domain walls as non-uniform magnetic charges (MCs). Quantum diamond imaging would help in visualization through MCs, such as irregularity in the material and relative orientation of magnetizations in neighboring domains.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"20 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139071073","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}
Heyi Li, Wenjie Miao, Qiujiao Du, Pai Peng and Fengming Liu
{"title":"All-pass phase shifting achieved by acoustic unidirectional guided resonances","authors":"Heyi Li, Wenjie Miao, Qiujiao Du, Pai Peng and Fengming Liu","doi":"10.35848/1882-0786/ad0f9f","DOIUrl":"https://doi.org/10.35848/1882-0786/ad0f9f","url":null,"abstract":"Phase manipulation of sound is an important function for many acoustic applications. Here, we apply temporal coupled mode theory to demonstrate that sound all-pass phase shifting, which means that acoustic waves propagate with unit amplitude but have strong phase changes, can be achieved by utilizing acoustic unidirectional guided resonances (AUGRs). An oblique layered acoustic structure with inversion-symmetry is proposed to realize AUGRs that radiate only to one side of the structure. Full-wave simulations are employed to validate the theoretical analysis. With the strong phase-only resonances, our proposed acoustic structure can find applications in acoustic filtering and sensing.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"25 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139072092","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}
Katsumi Kishino, Ai Mizuno, Tatsuya Honda, Jumpei Yamada and Rie Togashi
{"title":"Improving the luminous efficiency of red nanocolumn μ-LEDs by reducing electrode size to ϕ2.2 μm","authors":"Katsumi Kishino, Ai Mizuno, Tatsuya Honda, Jumpei Yamada and Rie Togashi","doi":"10.35848/1882-0786/ad10ec","DOIUrl":"https://doi.org/10.35848/1882-0786/ad10ec","url":null,"abstract":"A red InGaN-based nanocolumn micro μLED with an emission diameter of ϕ2.2 μm was demonstrated to achieve an on-wafer external quantum efficiency (EQE) of 2.1% at the peak wavelength of 615 nm. The LED was fabricated by repeating the electrode process on the same nanocolumn pattern area and reducing the emission diameter from ϕ80 to ϕ2.2 μm. The peak EQE, which was maximized at ∼25 A cm−2, increased by decreasing the emission diameter from 1.2% to 2.1%. This behavior, which differs from that of InGaN-film LEDs, is characterized as a unit of independent nano-LEDs with passivated sidewalls of nanocolumn LEDs.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"111 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055065","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}
{"title":"Hollow Mie resonators based on toroidal magnetic dipole mode with enhanced sensitivity in refractometric sensing","authors":"Rongyang Xu, Junichi Takahara","doi":"10.35848/1882-0786/ad197e","DOIUrl":"https://doi.org/10.35848/1882-0786/ad197e","url":null,"abstract":"We propose a refractometric sensor based on hollow silicon Mie resonators of a toroidal magnetic dipole mode. This mode has a pair of antiparallel electric dipoles perpendicular to the silica substrate; thus, the radiation of the mode is suppressed, resulting in an ultra-narrow reflection peak linewidth of 0.35 nm. In addition, the hollow structure enhances the interaction between the enhanced electric field and the surrounding medium, thus improving the sensitivity. The proposed Mie resonators achieve a sensitivity of 486 nm/RIU and a figure of merit up to 1389 RIU−1, which are ideal for refractometric sensing.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"16 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139150066","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}
Zhang Ting, Du Qiang, Wo Chengwen, Sun Li and Liu Xiaojun
{"title":"Acoustical routing based on diffraction inhibition in two-dimensional sonic crystal","authors":"Zhang Ting, Du Qiang, Wo Chengwen, Sun Li and Liu Xiaojun","doi":"10.35848/1882-0786/ad0cd7","DOIUrl":"https://doi.org/10.35848/1882-0786/ad0cd7","url":null,"abstract":"Routing and guiding acoustic waves without diffraction broadening and backscattering losses is of great interest to the acoustic community. Here, we propose a diffraction-immune acoustical waveguide based on diffraction inhibition in 2D sonic crystals (SCs). Due to the flat equal-frequency contour, the propagating acoustic waves can be highly localized between two neighboring rows of SCs. A few integrated sonic circuit building blocks including arbitrary angle bends and power splitters are further designed and theoretically realized. The proposed SCs open up possibilities for the flexible control of acoustic waves and lead to applications in integrated acoustical devices.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"17 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139071337","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}
{"title":"Demonstration of avalanche capability in 800 V vertical GaN-on-silicon diodes","authors":"Youssef Hamdaoui, Idriss Abid, Sondre Michler, Katir Ziouche and Farid Medjdoub","doi":"10.35848/1882-0786/ad106c","DOIUrl":"https://doi.org/10.35848/1882-0786/ad106c","url":null,"abstract":"High-quality pseudo-vertical p–n diodes using a GaN-on-silicon heterostructure are reported. An optimized fabrication process including a beveled deep mesa as edge termination and reduced ohmic contact resistances enabled high on-state current density and low on-resistance. A uniform breakdown voltage was observed at 830 V. The positive temperature dependence of the breakdown voltage clearly indicates the avalanche capability, reflecting both the high material and processing quality of the vertical p–n diodes. The Baliga figure of merit, around 2 GW cm−2, which is favorably comparable to the state-of-the-art, combined with avalanche capability paves the way for fully vertical GaN-on-Silicon power devices.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"9 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055068","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}
{"title":"Growth of metastable 2H-CaSi2 films on Si(111) substrates with ultrathin SiO2 films by solid phase epitaxy","authors":"Keiichiro Oh-ishi, Mikio Kojima, Takashi Yoshizaki, Arata Shibagaki, Takafumi Ishibe, Yoshiaki Nakamura and Hideyuki Nakano","doi":"10.35848/1882-0786/ad0e24","DOIUrl":"https://doi.org/10.35848/1882-0786/ad0e24","url":null,"abstract":"The Si-nano dot substrates formed using the ultrathin silicon oxide films were applied to fabricate CaSi2 films. The CaSi2 formed by this process was identified as the metastable phase 2H as the main component, and the 1H structure existed partially at the grains of the 2H phase. Although no experimental reports exist for the formation of 2H-CaSi2 crystal, the Si-nano dot substrates are considered as the high-entropy substrate to form the metastable phases. We experimentally determined the lattice parameter of the 2H phase by the annular dark field–scanning transmission electron microscopy observations using the Si as an internal standard sample.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"6 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054996","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}
Dongsheng Yuan, E. Vı́llora, D. Nakauchi, Takumi Kato, N. Kawaguchi, Takayuki Yanagida, Kiyoshi Shimamura
{"title":"Scattering-free Ce:LYBO single crystals for thermal neutron detection","authors":"Dongsheng Yuan, E. Vı́llora, D. Nakauchi, Takumi Kato, N. Kawaguchi, Takayuki Yanagida, Kiyoshi Shimamura","doi":"10.35848/1882-0786/ad1892","DOIUrl":"https://doi.org/10.35848/1882-0786/ad1892","url":null,"abstract":"Ce:Li6Y(BO3)3 (LYBO) is a well-known candidate for thermal neutron detection. So far, as-grown crystals exhibit a milky appearance that compromises their performance as scintillators. Current work demonstrates for the first time the growth of scattering-free LYBO by a thermal quenching process. The origin and features of the scattering centers are investigated in detail. Furthermore, the annealing treatment for the scintillation activation is studied, finding that the reduction in oxygen vacancies is mandatory. Under thermal neutron irradiation, the annealed scattering-free Ce:LYBO single crystal achieves a record-high light yield of 6200 ph/n in a single decay with a lifetime of 24 ns.","PeriodicalId":8093,"journal":{"name":"Applied Physics Express","volume":"28 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139159455","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}