[21a-C309-1~13] 6.1 Ferroelectric thin films

△ [21a-C309-12] Defect tolerant nature of shift current as revealed by photocurrent action spectra

〇(M2)Hiroki Hatada¹, Masao Nakamura^2,3, Yoshio Kaneko², Masato Sotome², Naoki Ogawa^2,3, Yoshinori Tokura^1,2, Masashi Kawasaki^1,2 (1.Univ. of Tokyo, 2.RIKEN-CEMS, 3.JST-PRESTO)

Keywords:shift-current, photovoltaic effect, ferroelectric material

Crystals with broken inversion symmetry, as exemplified by ferroelectric materials, are known to show photovoltaic effect. Recently, the origin of this effect is theoretically revealed to be so-called the shift current. Shift current of topological origin is expected to be insensitive to impurity and/or defect scatterings, which is in stark contrast with conventional photocurrent driven by electric field. In this study, we experimentally demonstrated the defect tolerant nature of shift current using a typical ferroelectric semiconductor SbSI. First, we revealed that shift current is almost constant even though samples show significant variation in dark conductance one by one. We also revealed that action spectrum with external bias is strongly affected by the surface recombination, whereas that without bias is not. These results clearly indicate the robustness of shift current against impurity, defect and surface recombination.