[20a-C601-1~10] 13.9 Compound solar cells

9:45 AM - 10:00 AM JST(12:45 AM - 1:00 AM UTC)

[20a-C601-4] Characterization of electronic structure at (Ba,Sn)S surface using photo-emission spectroscopy

〇Takehiko Nagai^1,4, Hidenobu Murata², Fumio Kawamura³, Hitoshi Tampo¹, Norio Terada^1,4 (1.AIST, 2.Osaka Metro Univ., 3.NIMS, 4.Kagoshima Univ.)

Keywords:

semiconductor compounds,photo-emission spectroscopy

In almost all tetrahedrally-coordinated semiconductors in practical use, such as Si, GaAs and CuInSe₂, the negative correlation between lattice constant and band gap (E_g) (E_g decreases with increasing the lattice constant) is well-known, which is one of a major guideline in material designs. However, recently, we have found that this relationship is positively correlated in SnS and GeS with low crystal symmetry from theoretical calculations. At present, however, it is unclear how this phenomenon is caused by a change in the electronic states of the valence and conduction bands. In this presentation, we will report the results which we individually measured the changes of density of states in the valence and conduction bands by photo-/inverse-photoelectron spectroscopy for a deeper understanding of this phenomenon.