[17a-D419-1~12] 6.4 Thin films and New materials

△ [17a-D419-9] Observation of low-temperature metallic conduction in MBE-grown CuI thin films

〇Takahiro Yasuami¹, Masao Nakamura², Naoki Ogawa^2,1, Yoshinori Tokura^1,2,3, Masashi Kawasaki^1,2 (1.Univ.of Tokyo, 2.RIKEN-CEMS, 3.Tokyo College)

Keywords:wide-gap semiconductor, Iodide, mobility

CuI is a representative wide bandgap semiconductor exhibiting excellent p-type conduction. However, there have been few reports on reliable low-temperature transport properties of CuI because of its large thermal expansion coefficient and high sensitivity to the surface adhesion of water and oxygen. In this talk, we report on the successful observation of metallic-like conduction down to low temperatures indicating degenerate conduction with a significant increase of mobility in MBE-grown CuI thin films by employing CaF₂ substrate , which has a thermal expansion coefficient close to that of CuI, and surface passivation with PbF₂.