Transport properties of n- and p-type polycrystalline BaSi2

THIN SOLID FILMS

卷:661

Article

Deng, T.¹  Suemasu, T.¹  Shohonov, D. A.²  Samusevich, I. S.²  Filonov, A. B.²  Migas, D. B.²  Borisenko, V. E.² 

[1] Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 3058573, Japan

[2] Belarusian State Univ Informat & Radioelect, Dept Micro & Nanoelect, P Browki 6, Minsk 220013, BELARUS

关键词: Barium disilicide;    Polycrystalline film;    Hall measurement;    Electron and hole mobilities;   

DOI  :  10.1016/j.tsf.2018.07.006

来源: Elsevier

【 摘 要 】

Electron and hole mobilities versus temperature in semiconducting barium disilicide (BaSi2) have been systematically studied both experimentally and theoretically. The experiments were performed with undoped 250 nm-thick BaSi2 polycrystalline films grown by molecular beam epitaxy. The grain size of films ranged from 0.2 to 5 mu m with the electron concentration of 5.0 x 10(15) cm(-3). To investigate the hole mobility, B-doped p-BaSi2 films with various dopant concentrations were fabricated and studied. The experimental temperature dependence of the electron mobility in the range of 160-300 K was found to have a maximum of 1230 cm(2)/V.s at 218 K, while at room temperature (RT) it dropped down to 816 cm(2)/V.s. We demonstrate that the temperature dependence of the electron mobility cannot be adequately reproduced by involving standard scattering mechanisms. A modified approach accounting for the grained nature of the films has been proposed for the correct description of the mobility behavior. The highest hole mobility in p-BaSi2 films reaching similar to 80 or 200 cm(2)/V.s (for the films grown on (111) or (001) Si substrates, respectively) at RT is about an order or four times of magnitude smaller than that in n-BaSi2 films. Such a great difference we ascribe to the specific features of electron-phonon and hole-phonon coupling in semiconducting BaSi2.

【 授权许可】

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