The 81st JSAP Autumn Meeting, 2020

Presentation information

Oral presentation

13 Semiconductors » 13.2 Exploratory Materials, Physical Properties, Devices

[11p-Z01-1~11] 13.2 Exploratory Materials, Physical Properties, Devices

Fri. Sep 11, 2020 12:30 PM - 3:30 PM Z01

Yoshiaki Nakamura(Osaka Univ.), Kenji Yamaguchi(QST)

1:00 PM - 1:15 PM

[11p-Z01-3] Optical properties improvement of lightly and heavily boron-doped BaSi2 by atomic H passivation

〇(D)Zhihao Xu1, Kaoru Toko1, Takashi Suemasu1 (1.Univ. Tsukuba)

Keywords:H passivation

Semiconducting BaSi2 has many advantages for solar cell applications, such as a suitable band gap of 1.3 eV, a large absorption coefficient of 3 × 104 cm-1 at 1.5 eV, and a large minority-carrier diffusion length of ca. 10 μm [1]. The first-principle calculation predicts Si vacancies to be most likely to occur as point defects in BaSi2 regardless of Si-rich or Si poor growth conditions and lead to the degradation of the minority-carrier properties of BaSi2[2]. Therefore, we try to passivate defects in undoped BaSi2 films by atomic hydrogen (H). The photoresponsivity of undoped BaSi2 films is enhanced markedly by irradiation of atomic H after the growth of BaSi2 films for 15 min thanks to the improvement of minority carrier lifetime [3]. The basic solar cell structure is pn junction. Thus, the passivation of impurity-doped p- or n-BaSi2 films is of particular importance. In this study, we investigate the effect of atomic H passivation on the photoresponsivity property of lightly (p = 7 × 1016 cm-3) and heavily (p = 3 × 1018 cm-3) boron (B) -doped p-BaSi2.