Abstract The structural, elastic and electronic properties of KT-GaBP 2 under pressure ranging from 0 to 70 GPa were investigated by using density functional theory. The elastic stiffness constants were calculated under different pressures and found that the single crystal KT-GaBP 2 is elastically stable in the range from 0 to 70 GPa, and afterwards becomes unstable. It can be inferred that the phase transition may occur in the range of 70 ∼ 80 GPa. The universal anisotropy index of single crystal KT-GaBP 2 , as well as the elastic moduli and Debye temperature for the polycrystal KT-GaBP 2 were calculated under different pressures, and the effect of pressure on the elastic properties was studied further. It is found that the single crystal KT-GaBP 2 is elastically anisotropic and that the anisotropy increases monotonically with increasing pressure. The polycrystal KT-GaBP 2 inclines to resist better volume compression than shape deformation, and it will possess a best thermal conductivity under a certain pressure value within the range of 25 ∼ 35 GPa. Finally, the electronic properties of KT-GaBP 2 induced by pressure were studied and found that the energy gap decreases monotonically with increasing pressure. Furthermore, the direct energy gap changes into an indirect one as the pressure up to about 70 GPa.

中文翻译：

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KT-GaBP2 半导体在压力下的结构、弹性和电子特性的第一性原理研究

摘要 采用密度泛函理论研究了KT-GaBP 2 在0~70 GPa压力下的结构、弹性和电子性质。计算不同压力下的弹性刚度常数，发现单晶KT-GaBP 2 在0-70 GPa范围内弹性稳定，之后变得不稳定。可以推断，相变可能发生在 70 ～ 80 GPa 的范围内。计算了不同压力下单晶KT-GaBP 2 的通用各向异性指数，以及多晶KT-GaBP 2 的弹性模量和德拜温度，进一步研究了压力对弹性性能的影响。发现单晶KT-GaBP 2 是弹性各向异性的，并且各向异性随着压力的增加而单调增加。多晶KT-GaBP 2 倾向于抵抗比形状变形更好的体积压缩，并且在25 ∼ 35 GPa范围内的一定压力值下将具有最佳热导率。最后，研究了压力引起的KT-GaBP 2 的电子性质，发现能隙随着压力的增加而单调减小。此外，当压力达到约 70 GPa 时，直接能隙变为间接能隙。