Covalent semiconductor materials are indispensable for the development of modern society because of their excellent semiconductor properties, but they are consistently challenged by failures due to brittle fracture. Recently, both experimental and theoretical attempts to modify the strength of materials by electron doping have been reported. Here, we comprehensively examine the impact of excess electrons and holes on the bonding strength of a typical covalent material based on first-principles calculations. The bond strength is reduced or increased monotonically and linearly with electron doping density, resulting in an approximate 60 % variation at the highest feasible doping density. The degree of strength change per carrier density for each material is found to correlate with its bonding characteristics, with stronger ionic bonding properties exhibiting larger changes. Furthermore, the quantum mechanism of the change in strength is explained by energetic contribution of bonding orbitals occupied by introduced charge. These results indicate that covalent semiconductor materials share a common mechanism of strengthening by electron doping, which could contribute to the design of more robust semiconductor products.

中文翻译：

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过量电子/空穴掺杂对共价半导体材料的量子电子强化


共价半导体材料因其优异的半导体性能而成为现代社会发展中不可或缺的材料，但由于脆性断裂，它们一直受到故障的挑战。最近，通过电子掺杂来改变材料强度的实验和理论尝试都有报道。在这里，我们基于第一性原理计算全面研究了过量电子和空穴对典型共价材料键合强度的影响。键合强度随电子掺杂密度单调线性地降低或增加，导致在最高可行掺杂密度下变化约 60%。发现每种材料单位载流子密度的强度变化程度与其键合特性相关，离子键合性能越强，变化越大。此外，强度变化的量子机制可以用引入电荷占据的键合轨道的能量贡献来解释。这些结果表明，共价半导体材料具有通过电子掺杂增强的共同机制，这可能有助于设计更稳健的半导体产品。