[18p-P6-1~18] 13.2 Exploratory Materials, Physical Properties, Devices

▲ [18p-P6-10] Surface passivation effect of RF-plasma processed a-Si:H layers
on the optical properties of BaSi₂ epitaxial films

〇(M2)Zhihao Xu¹, Kazuhiro Gotoh², Tianguo Deng¹, Kaoru Toko¹, Noritaka Usami², Takashi Suemasu¹ (1.Univ Tsukuba, 2.Nagoya Univ)

Keywords:BaSi2

BaSi₂ is a good candidate for future solar cells. It has many advantages such as a band gap of 1.3 eV, suitable for the solar spectrum, a large absorption coefficient of 3 × 10⁴ cm^-1 at 1.5 eV, exceeding those of CIGS, and a large minority-carrier diffusion length of ca. 10 μm. In our previous work, we have realized the conversion efficiency of 9.9% in a p-BaSi₂/n-Si (111) heterojunction solar cell capped with pure amorphous Si (a-Si) layers. They have, however, a lot of dangling bonds to hinder the performance of solar cell. An alternative is hydrogenated a-Si (a-Si:H) layer. We have already confirmed that a-Si:H can be grown by MBE method and radio-frequency (RF) plasma generator. In this study, we investigated the effect of a-Si:H capping layers on the optical properties of crystalline Si (c-Si) substrates and BaSi₂ epitaxial films.