Presentation Information
[7a-P05-79]Observation of Shift Current in Bulk GeSe during Antiferroelectric to Ferroelectric Phase Transition
〇Joanne Martinez1, Shinichiro Matano1, Kazunari Matsuda1 (1.Kyoto Univ.)
Keywords:
Shift Current,Bulk Photovoltaic Effect,Ferroelectric Transition
Recently, bulk photovoltaic effects have been intensively studied in two-dimensional materials for solar cell applications without the need for a p–n junction. Group IV monochalcogenides MX (M = Ge, Sn; X = S, Se) have attracted attention due to their non-centrosymmetry in monolayer form, where large effects such as shift current are expected. GeSe has shown to exhibit antiferroelectricity (AFE) and ferroelectricity (FE), with an electric-field-induced AFE–FE phase transition. In this work, we studied the current–voltage (I–V) characteristics of bulk GeSe under light illumination. In the application of lower voltage (<10 V), the current–voltage curve shows almost linear behavior; however, nonlinear large hysteresis is clearly observed, suggesting the AFE–FE transition. At higher applied voltage (>12 V), significant increases in spontaneous photocurrent at 0 V are clearly observed, indicating the emergence of shift current. SHG results under bias will also be discussed.