講演情報
[22p-P09-4]First-principles calculation of bulk photovoltaic effect in ferroelectric topological insulator phase of halide perovskite
〇YedijaYusua Sibuea Teweng1, Naoya Yamaguchi2, Fumiyuki Ishii2 (1.Grad.Sch.of Sci.Tech, 2.NanoMaRi)
キーワード：
Bulk photovoltaic effect、Topological insulator、Ferroelectrics
Generating photocurrent in condensed matter is one of the main topics for photovoltaic and optoelectronic applications. A single-phase bulk material without inversion symmetry can generate a direct current under light illumination. This current generation mechanism, called as the bulk photovoltaic effect (BPVE), does not rely on p-n heterojunctions. Shift current has considered as a dominant contributor of BPVE in ferroelectric materials. Halide perovskites have attracted much interest for application on next-generation solar cell materials. In recent years, many theoretical investigations have found that CsPbI3 may exhibit a topological insulator phase under hydrostatic pressure. Since the cubic phase of CsPbI3 was predicted to induce a ferroelectric phase under hydrostatic pressure, it is expected to generate a bulk photocurrent in the structure. In this study, we performed first-principles calculations for bulk CsPbI3 structure and evaluated the shift current conductivity with respect to the band gap energy and electric polarization. We evaluated the ferroelectric topological insulator (FETI) phase by investigating the electronic structure. We also discussed the possibility to detect the topological phase transition in topological insulating material through the shift current calculation.