Four new sp³-hybridized silicon allotropes (Si₁₀, Si₁₄, Si₂₀-I, and Si₂₀-II) in the space groups of P2₁/m and P2/m were developed in this study. Their values for properties related to stability, and mechanical, electronic, and optical properties were investigated using the first-principles method. Compared with most previously predicted and synthesized silicon phases, these allotropes exhibit lower energy, which are only 0.042, 0.037, 0.056, and 0.120 eV/atom higher than that of diamond-Si. These silicon allotropes are direct or quasi-direct semiconductors with band gaps in the range of 1.193–1.473 eV, and exhibit stronger photon absorption in the visible and ultraviolet regions than diamond-Si. In addition, they exhibit excellent mechanical properties, such as stronger resistance to linear compression than diamond-Si and higher hardness than most previously reported phases of silicon. Given their low energy, direct or quasi-direct band gap, and strong capacity for absorbing solar energy, these four silicon materials have potential for use in thin-film solar cells and photovoltaic devices.

在P 2 ₁ / m和P 2 / m的空间群中有四个新的sp ^3-杂化硅同素异形体（Si ₁₀，Si ₁₄，Si ₂₀ -I和Si ₂₀ -II）在这项研究中得到发展。使用第一原理方法研究了它们与稳定性以及机械，电子和光学特性相关的特性值。与大多数先前预测和合成的硅相相比，这些同素异形体显示出较低的能量，仅比金刚石-Si高0.042、0.037、0.056和0.120 eV /原子。这些硅同素异形体是带隙在1.193–1.473 eV范围内的直接或准直接半导体，并且在可见光和紫外光区域的吸收率比金刚石Si强。此外，它们还具有出色的机械性能，例如比金刚石-Si更好的抗线性压缩性能，并且比大多数先前报道的硅相具有更高的硬度。由于它们的能量低，直接或准直接带隙，