• Kaori Miyazaki

      Articles written in Bulletin of Materials Science

    • Quantum chemical studies on initial surface process ina-Si: H plasma CVD

      Hideomi Koinuma Kenji Nakajima Kaori Miyazaki

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      The surface morphology ofa-Si: H is strongly dependent on substrate material and temperature, especially in the initial stage of deposition. Furthermore, some surface treatments could induce a drastic change in the initial growth mode. For example, the hydrogen plasma treatment of highly oriented pyrolytic graphite (HOPG) surface prior toa-Si: H deposition changed the growth mode from inhomogeneous to homogeneous one. In order to elucidate this surface chemical process, molecular orbital calculations were performed and compared with the experimental observation of the surface by AFM and STM. The calculation verified hydrogen addition tosp2 carbons on HOPG to facilitate the bonding of SiH3 to neighbouring carbons, which correspond to the nucleation or pinning of precursors as the origin of homogeneous growth ofa-Si: H film.

    • Device simulation and fabrication of field effect solar cells

      Kaori Miyazaki Nobuyuki Matsuki Hiroyuki Shinno Hiroshi Fujioka Masaharu Oshima Hideomi Koinuma

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      The performance of a novel hydrogenated amorphous silicon (a-Si : H) solar cell which utilizes the field effect solar cell (FESC) has been investigated both theoretically and experimentally. The theoretical analysis has been done for bothp- andn-channel FESCs by employing a two-dimensional device simulator which is based on current continuity and Poisson equations. The calculated performance is compared with that of conventional (p-i-n)a-Si : H solar cells. The calculation demonstrated that bothn-channel andp-channel FESCs could improve the conversion efficiency by as much as 50%.

      In order to check the reliability of simulation, the transport properties of intrinsica-Si : H film and thin film transistor (TFT) have also been calculated and compared with the experimentally obtained characteristics. Experimental verification of TFT and FESC has been attempted by using MgO anda-SiN : H as dielectric layer materials. Preliminary results are presented.

    • A novela-Si : H solar cell designed by two-dimensional device simulation

      Kaori Miyazaki Hiroshi Fujioka Masaharu Oshima Hideomi Koinuma

      More Details Abstract Fulltext PDF

      The performance of a novel hydrogenated amorphous silicon (a-Si : H) solar cell that utilizes the field effect (field effect solar cell (FESC)) has been investigated theoretically. The analysis has been done for bothp- andn-channel FESCs, employing a two-dimensional device simulator which is based on current continuity and Poisson equations. The calculation predicted that bothn-channel andp-channel FESCs could offer improved conversion efficiency as compared with the conventional-dopedp-i-n solar cell with equal qualityi (intrinsic)-layer. The observed improvement can be mainly attributed to the quantum-efficiency increase for high-energy photons. Cell parameters that may affect the energy conversion efficiency of FESCs have also been evaluated with the simulator.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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