[19p-133-1~19] 6.1 Ferroelectric thin films

△ [19p-133-16] Verification of shift current independent on carrier mobility by optimizing electrodes

〇(M1)Hiroki Hatada¹, Masao Nakamura^2,3, Yoshio Kaneko², 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 typified 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 is a topological photocurrent insensitive to the carrier mobility in the bulk crystals, which is a sharp contrast with conventional photocurrent. However, the distinctive feature of shift current has not been fully verified in experiments, presumably due to the formation of Schottky barrier at the sample-electrode interface. In this study, we investigated in detail the impact of electrodes on the extraction of shift current using a representative ferroelectric semiconductor SbSI. By reducing the effect of Schottky barrier, we succeeded in observing photocurrent whose magnitude is independent of the mobility. This is a first clear indication of the dissipation-less nature of the shift current.