[15a-1E-1~10] 3.13 Semiconductor optical devices

[15a-1E-1] Solar Hydrogen Evolution using ZnSe-Cu(In,Ga)Se₂ Thin Film

〇(M2)Hiroyuki Kaneko¹, Tsutomu Minegishi¹, Kazunari Domen¹ (1.Tokyo Univ.)

Keywords:thin film,CIGS,photoelectrode

It has been reported that Cu(In,Ga)Se₂ photocathode shows a large photocurrent value of 30 mA/cm² at 0 V_RHE under simulated sunlight. However, efficient solar-to-hydrogen conversion system has not been demonstrated using the CIGS photocathode due to the low onset potential. Onset potential strongly depends on the valence band maximum (VBM) level. Therefore, in this study, we prepared a solid solution using ZnSe, which possesses deeper VBM than CIGS, as a thin film to improve onset potential. In the presentation, characterization of the ZnSe-CIGS thin films and the photoelectrochemical properties will be discussed.