Germanium selenide is a promising material for electronic, photovoltaic, and thermoelectric applications; however, structural phase transitions of GeSe under pressure are controversial. Combining evolutionary algorithms, density functional theory, tight-binding method, and laser-heated diamond anvil cell experiments, pressure-induced phase transitions of GeSe are thoroughly investigated. Two novel intermediate phases are predicted to exist in between the well-known α-GeSe and the recently discovered β-GeSe under high pressure. α-GeSe is found to transform into a rhombohedral crystal structure with a space group of R3m at a low hydrostatic pressure. The R3m phase of GeSe exhibits robust ferroelectricity analogous to GeTe. By further increasing the pressure to approximately 6 GPa, the R3m phase is predicted to transform into a rock-salt structure, becoming a 3D topological crystalline insulator with an inverted band structure. The newly discovered GeSe high-pressure phases greatly enrich our knowledge of IV–VI compounds.

硒化锗是用于电子，光伏和热电应用的有前途的材料。然而，GeSe在压力下的结构相变是有争议的。结合进化算法，密度泛函理论，紧密结合方法和激光加热金刚石砧细胞实验，对GeSe的压力诱导相变进行了深入研究。在高压下，众所周知的α-GeSe和最近发现的β-GeSe之间将存在两个新的中间相。发现在低静水压下，α-GeSe转变为具有R 3 m空间群的菱面体晶体结构。的[R 3米GeSe相具有类似于GeTe的强固铁电性。通过将压力进一步提高到大约6 GPa，可以预测R 3 m相将转变为岩盐结构，成为具有倒带结构的3D拓扑晶体绝缘体。新发现的GeSe高压相极大地丰富了我们对IV-VI化合物的了解。