[20p-C302-1~12] 6.4 Thin films and New materials

[20p-C302-6] Modification of band structures in orientation-controlled CuI films under epitaxial strain

〇Masao Nakamura¹, Sotaro Inagaki², Yoshihiro Okamura², Makiko Ogino², Youtarou Takahashi^1,2, Kiyohiro Adachi¹, Daisuke Hashizume¹, Yoshinori Tokura^1,2,3, Masashi Kawasaki^1,2 (1.RIKEN-CEMS, 2.Univ. of Tokyo, 3.Tokyo College)

Keywords:wide-bandgap semiconductor, epitaxial thin film, exciton

Cuprous iodide (CuI) is a representative p-type wide-bandgap semiconductor. We fabricated orientation-controlled single-crystalline thin films of cuprous iodide (CuI) on nearly lattice-matched InAs substrates by molecular beam epitaxy. The fabricated thin films exhibit sharp exciton resonant structures reflecting the high crystallinity. From the exciton resonances, we investigated in detail the temperature and substrate-orientation dependences of the band gap and band splitting associated with the epitaxial strain, and determined the deformation potentials that relate the strain to the band structure modification.