Updated on 2021/11/12

写真a

 
TOMIDA Daisuke
 
Organization
Institute of Materials and Systems for Sustainability Center for Integrated Research of Future Electronics Innovative Devices Section Designated associate professor
Title
Designated associate professor

Degree 1

  1. 博士(工学) ( 2006.3   東北大学 ) 

 

Papers 5

  1. Facile method for the synthesis of zinc- or magnesium-doped gallium nitride powders from gallium metal Reviewed

    Daisuke Tomida, Quanxi Bao, Makoto Saito, Kouhei Kurimoto, Kazunobu Kojima, Kun Qiao, Tohru Ishiguro, Shigefusa F. Chichibu

    Journal of Crystal Growth   Vol. 570   page: 126190 - 126190   2021.5

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    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:Elsevier BV  

    DOI: 10.1016/j.jcrysgro.2021.126190

  2. Numerical simulation of ammonothermal crystal growth of GaN-current state, challenges, and prospects Reviewed

    Schimmel S., Tomida D., Ishiguro T., Honda Y., Chichibu S., Amano H.

    Crystals   Vol. 11 ( 4 )   2021.4

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    Language:English   Publisher:Crystals  

    Numerical simulations are a valuable tool for the design and optimization of crystal growth processes because experimental investigations are expensive and access to internal parameters is limited. These technical limitations are particularly large for ammonothermal growth of bulk GaN, an important semiconductor material. This review presents an overview of the literature on simulations targeting ammonothermal growth of GaN. Approaches for validation are also reviewed, and an overview of available methods and data is given. Fluid flow is likely in the transitional range between laminar and turbulent; however, the time-averaged flow patterns likely tend to be stable. Thermal boundary conditions both in experimental and numerical research deserve more detailed evaluation, especially when designing numerical or physical models of the ammonothermal growth system. A key source of uncertainty for calculations is fluid properties under the specific conditions. This originates from their importance not only in numerical simulations but also in designing similar physical model systems and in guiding the selection of the flow model. Due to the various sources of uncertainty, a closer integration of numerical modeling, physical modeling, and the use of measurements under ammonothermal process conditions appear to be necessary for developing numerical models of defined accuracy.

    DOI: 10.3390/cryst11040356

    Scopus

  3. Boundary Conditions for Simulations of Fluid Flow and Temperature Field during Ammonothermal Crystal Growth—A Machine-Learning Assisted Study of Autoclave Wall Temperature Distribution Reviewed

    Saskia Schimmel, Daisuke Tomida, Makoto Saito, Quanxi Bao, Toru Ishiguro, Yoshio Honda, Shigefusa Chichibu, Hiroshi Amano

    Crystals   Vol. 11 ( 3 ) page: 254 - 254   2021.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:MDPI AG  

    Thermal boundary conditions for numerical simulations of ammonothermal GaN crystal growth are investigated. A global heat transfer model that includes the furnace and its surroundings is presented, in which fluid flow and thermal field are treated as conjugate in order to fully account for convective heat transfer. The effects of laminar and turbulent flow are analyzed, as well as those of typically simultaneously present solids inside the autoclave (nutrient, baffle, and multiple seeds). This model uses heater powers as a boundary condition. Machine learning is applied to efficiently determine the power boundary conditions needed to obtain set temperatures at specified locations. Typical thermal losses are analyzed regarding their effects on the temperature distribution inside the autoclave and within the autoclave walls. This is of relevance because autoclave wall temperatures are a convenient choice for setting boundary conditions for simulations of reduced domain size. Based on the determined outer wall temperature distribution, a simplified model containing only the autoclave is also presented. The results are compared to those observed using heater-long fixed temperatures as boundary condition. Significant deviations are found especially in the upper zone of the autoclave due to the important role of heat losses through the autoclave head.

    DOI: 10.3390/cryst11030254

    Scopus

  4. Ammonothermal growth of 2 inch long GaN single crystals using an acidic NH4F mineralizer in a Ag-lined autoclave Reviewed

    Daisuke Tomida, Quanxi Bao, Makoto Saito, Ryu Osanai, Kohei Shima, Kazunobu Kojima, Tohru Ishiguro, Shigefusa F. Chichibu

    Applied Physics Express   Vol. 13 ( 5 ) page: 055505-1 - 5   2020.4

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    Authorship:Lead author, Corresponding author  

  5. Thermal Conductivity Measurements of Liquid Ammonia by the Transient Short‑Hot‑Wire Method Reviewed

    Daisuke Tomida, Tohru Yoshinaga

    International Journal of Thermophysics   Vol. 5 ( 41 ) page: 53   2020.3

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    Authorship:Lead author, Corresponding author  

Books 1

  1. Ammonothermal Synthesis and Crystal Growth of Nitrides

    Daisuke Tomida, Makoto Saito, Quanxi Bao, Tohru Ishiguro, Shigefusa F. Chichibu( Role: Joint author ,  Chapter 5, Innovative Techniques for Fast Growth and Fabrication of High Purity GaN Single Crystals, pp.65-76)

    Springer  2021.2 

Presentations 4

  1. PVT properties of the ammonia + ammonium halide mixtures

    Daisuke Tomida

    日本化学会第100春季年会 

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    Event date: 2020.3

  2. Simulation of the global thermal field in a setup for ammonothermal growth of GaN

    Saskia Carola Schimmel, Daisuke Tomida, Makoto Saito, Quanxi Bao, Toru Ishiguro, Yoshio honda, Shigefusa F. Chichibu, Hiroshi Amano

    第68回 応用物理学会春季学術講演会  2021.3.17 

  3. Evaluation of realistic boundary conditions for simulations of ammonothermal GaN crystal growth

    S. Schimmel, D. Tomida, M. Saito, Q. Bao, T. Ishiguro, Y. Honda, S. F. Chichibu, H. Amano

    The 8th Asian Conference on Crystal Growth and Crystal Technology  2021.3.2 

  4. Thermal conductivity measurements of liquid ammonia by the transient short-hot-wire method

    Daisuke Tomida, Tohru Yoshinaga, Chiaki Yokoyama

    The 12th Asian Thermophysical Properties Conference  2019.10.2