Theoretical study on photoelectric properties of ferroelectric photovoltaic perovskite CsGeBr 3 based on first-principle calculations

作者：Chun-Jie Zhong, Jun Luo, Ling-Yu Pan, Biao Liu, Junliang Yang, Meng‐Qiu Cai · 发表于：Physica Scripta · 年份：2024 · DOI：10.1088/1402-4896/ad4749 · 被引用次数：10 · 研究领域：Perovskite Materials and Applications、Solid-state spectroscopy and crystallography

Abstract Ferroelectric photovoltaic materials have attracted great attention because of their unique photoelectric conversion mechanism, high photo-generated voltage, and adjustable polarization intensity. Traditional ferroelectric oxide perovskites such as BaTiO 3 , BiFeO 3 , and Pb(ZrTi)O 3 have attracted much attention but they are not suitable as light absorbing layers in solar cells, due to the large optical bandgap, low light absorption rate, and small photogenerated current. Therefore, it is necessary to seek prominent materials with both ferroelectric and suitable band gaps. Recently, the evidence of ferroelectricity in the typical three-dimensional all-inorganic halide perovskites CsGeX 3 , with band gaps of 1.6 eV to 2.3 eV has been confirmed. However, the spontaneous polarization of ferroelectric perovskite CsGeX 3 is ∼10 to 20 μ c cm −2 which is weaker than that of ABO 3 (∼26 to 75 μ c cm −2 ). Strain engineering has a significant influence on the properties of semiconductor materials by controlling the lattice scaling and the internal atomic spacing. Hence, in this work, strain engineering is introduced to adjust the ferroelectric polarization and the photoelectric properties of ferroelectric perovskite CsGeBr 3 . The calculated results show that when the applied compressive strain increases from 0% to −4%, the spontaneous polarization of ferroelectric perovskite CsGeBr 3 increases from 14.23 μ c cm −2 to 51.61 μ c cm −2 , and the band gap reduces from 2.3631 eV ...