[20p-W641-1~9] State-of-the-art characterization technique of dielectric and ferroelectric materials

[20p-W641-5] Defect Control in Ferroelectric LiNbO₃
Toward Enhanced Photovoltaic Effect under Visible Light Illumination

〇Atsushi Inuzuka¹, Shusuke Takahashi¹, Kota Yoshida¹, Ryotaro Inoue², Yuji Noguchi¹, Masaru Miyayama¹ (1.Univ. of Tokyo, 2.Nihon Univ.)

Keywords:ferroelectrics,defect control,DFT calculation

The purpose of this study is to establish the defect control guideline for enhanced photovoltaic effect in ferroelectrics under visible light illumination. We select lithium niobate as a model ferroelectric material and choose 3d transition metal elements of Fe, Mn, and Cu as the active centers for visible light absorption. Here, we report the defect states arising from the transition metal elements inside the band gap of lithium niobate obtained by DFT calculations and investigate the photovoltaic properties obtained for single-crystalline thin films of heavily -doped lithium niobate.