Abstract

We report the electronic, vibrational, and optical properties of specific double perovskites, i.e., \(\textrm{Ba}_{2}\textrm{YBiO}_{6}\) (BYBO) and \(\textrm{Ba}_{2}\textrm{ScBiO}_{6}\) (BSBO) using first-principle calculations based on density functional theory. The stability of both the compounds has been confirmed by their elastic and thermodynamic properties. The effects of strain on the electronic and optical properties of BYBO and BSBO; with an external range of \(-5\) to \(+5\%\) . Electronic properties show semiconducting behavior with bandgap ( \(E_{\textrm{g}}\) ) values of; \(E_{\textrm{g}} = 1.68 \,\hbox {eV}\) and \(E_{\textrm{g}} = 1.35 \,\hbox {eV}\) , for BYBO and BSBO, respectively with indirect bandgap alignment. On application on external tensile strain \(\ge +3\%\) , the bandgap of BYBO and BSBO undergoes a transition from indirect alignment to direct alignment, whereas the electronic bandgap alignment does not change with compressive strain. Interestingly, the magnitude of the bandgap shows contrasting behavior, i.e., the bandgap increases (up to 0.9–1 eV) with compressive strain and decreases (up to 0.7–0.8 eV) with tensile strain. The wavelength values calculated in the absorption spectra of the pristine samples are 373 nm for BYBO and 434 nm for BSBO; suggesting their potential suitability as alternatives for “solar cell” applications, photodetectors, superlenses, photovoltaic devices, etc.

中文翻译：

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研究双轴应变对 $$\textrm{Ba}_{2}\textrm{YBiO}_{6}$$ 和 $$\textrm{Ba}_{2}\textrm{ 电子和光学性质的影响ScBiO}_{6}$$ 用于光电应用的双钙钛矿：从头计算

摘要

我们报告了特定双钙钛矿的电子、振动和光学特性，即\(\textrm{Ba}_{2}\textrm{YBiO}_{6}\) (BYBO) 和\(\textrm{Ba} _{2}\textrm{ScBiO}_{6}\) (BSBO) 使用基于密度泛函理论的第一原理计算。这两种化合物的稳定性已通过其弹性和热力学性质得到证实。应变对BYBO和BSBO电子和光学性能的影响；外部范围为\(-5\)到\(+5\%\)。电子特性显示半导体行为，带隙 ( \(E_{\textrm{g}}\) )值为；\(E_{\textrm{g}} = 1.68 \,\hbox {eV}\)和\(E_{\textrm{g}} = 1.35 \,\hbox {eV}\)，分别对于 BYBO 和 BSBO具有间接带隙对准。在施加外部拉伸应变\(\ge +3\%\)时，BYBO 和 BSBO 的带隙经历了从间接对准到直接对准的转变，而电子带隙对准不随压缩应变而改变。有趣的是，带隙的大小表现出相反的行为，即带隙随着压缩应变而增加（高达 0.9-1 eV），随着拉伸应变而减小（高达 0.7-0.8 eV）。在原始样品的吸收光谱中计算出的波长值：BYBO 为 373 nm，BSBO 为 434 nm；表明它们可能适合作为“太阳能电池”应用、光电探测器、超级透镜、光伏设备等的替代品。