Density functional theory investigation of the LiIn1-xGaxSe2 solid solution

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• 作者：Brenden Wiggins ; Enrique Batista ; Arnold Burger ; Keivan Stassun and Ashley Stowe
• 刊名：physica status solidi (b)
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：253
• 期：8
• 页码：1465-1471
• 全文大小：1302K
• ISSN：1521-3951

文摘

The electronic structure and optical properties of the LiIn_1–xGa_xSe₂ (x = 0, 0.25, 0.5, 0.75, 1) solid solution were studied by density functional theory (DFT) with pure functionals. The exchange-correlation is treated within the local density approximation (LDA) and generalized-gradient approximation (GGA). The electronic structures for each respective compound are discussed in detail. Calculations reveal that gallium incorporation can be used to tune the optical-electrical properties of the solid solution and correlates with the lattice parameter. The band gap trend of the LiIn_1–xGa_xSe₂ system follows a nonlinear behavior between the LiInSe₂ and LiGaSe₂ ternary boundaries. The bowing parameter is estimated to be on the order of 0.1–0.3 eV at the Γ-point. Low-temperature optical absorption revealed a 30% change in the temperature dependence of the band gap for the intermediate compound LiIn_0.6Ga_0.4Se₂ compared to ternary boundaries and suggests the heat capacity to be another control element through strain.