Abstract In this work, the structural, mechanical, electronic and optical properties of Be3X2 (X = N, P, As) were studied using first-principles calculations. Structural parameters of Be3N2 and Be3P2 agree well with their experimental values. The calculated band gap of Be3N2 is in good agreement with the available experimental value. Moreover, the calculated results show that three compounds are found to have direct band gaps. The band gaps of Be3P2 and Be3As2 are 1.12 and 0.92 eV, respectively, which are potential candidate materials for solar absorber applications. Moreover, the band gap of Be3P2 can be tuned from 0.70 to 1.40 eV by applying the hydrostatic strain. Be3P2 and Be3As2 exhibit strong and wide optical absorption in the light spectrum. The elastic constants and moduli were studied for the first time, and the results imply that all compounds are brittle materials. Our work is helpful to explore potential materials for applications in optoelectronic devices.

中文翻译：

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第一性原理洞察 Be3X2 (X = N, P, As) 的结构、机械、电子和光学特性

摘要 在这项工作中，使用第一性原理计算研究了 Be3X2 (X = N, P, As) 的结构、机械、电子和光学特性。Be3N2 和 Be3P2 的结构参数与它们的实验值非常吻合。Be3N2 的计算带隙与可用的实验值非常吻合。此外，计算结果表明发现三种化合物具有直接带隙。Be3P2 和 Be3As2 的带隙分别为 1.12 和 0.92 eV，它们是太阳能吸收器应用的潜在候选材料。此外，通过施加静水应变，Be3P2 的带隙可以在 0.70 到 1.40 eV 之间调整。Be3P2 和 Be3As2 在光谱中表现出强而宽的光吸收。首次研究了弹性常数和模量，结果表明所有化合物都是脆性材料。我们的工作有助于探索在光电器件中应用的潜在材料。