[14p-PB8-1~8] 13.2 Exploratory Materials, Physical Properties, Devices

▲ [14p-PB8-2] Marked photoresponsivity enhancement and minority carrier lifetime increase of boron-doped BaSi2 by atomic H passivation

〇(D)Zhihao Xu¹, Kazuhiro Gotoh², Kaoru Toko¹, Noritaka Usami², Takashi Suemasu¹ (1.Univ. Tsukuba, 2.Nagoya Univ.)

Keywords:H passivation

Introduction 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 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 onto BaSi2 films for 15 min thanks to the improvement of minority carrier lifetime [3]. The basic solar cell structure is a pn junction. Thus, 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 photoresponse property and minority carrier lifetime of B-doped p-BaSi2