[15a-B3-1~9] 13.2 探索的材料物性・基礎物性

▲ [15a-B3-7] Fabrication of nitrogen-doped BaSi₂ films on Si(111) by molecular beam epitaxy

〇Zhihao Xu¹、Tianguo Deng¹、Ryota Takabe¹、Miftahullatif Emha Bayu¹、Kaoru Toko¹、Takashi Suemasu¹ (1.Univ. Tsukuba)

キーワード：Nitrogen doped barium disicide

BaSi₂ is a good candidate for future solar cell material, because its band gap is 1.3 eV, suitable for the solar spectrum. Besides, it also has a large absorption coefficient 3×10⁴ cm^-1 at 1.5 eV [1]. The minority-carrier diffusion length of undoped BaSi₂ is approximately 10 μm [2]. On the basis of these results, we aim to realize BaSi₂ pn junction solar cells. For n-type BaSi₂, we once attained the electron concentration of 10²⁰ cm^-3 for Sb-doped BaSi₂[3], whereas Sb is easy to diffuse into other layers [4], which might destroy a sharp pn junction required for solar cell. Therefore, exploring alternative donor impurity is very important. BaSi₂ films doped with a Group 15^th element (P, As, Sb) except N have been grown, which all exhibit the n-type conductivity. In this study, we attempted to form N-doped BaSi₂ films and characterized their properties.