Earth-abundant antimony trisulfide (Sb₂S₃), or simply antimonite, is a promising material for capturing natural energies like solar power and heat flux. The layered structure, held up by weak van-der Waals forces, induces anisotropic behaviors in carrier transportation and thermal expansion. Here, we used stress as mechanical stimuli to destabilize the layered structure and observed the structural phase transition to a three-dimensional (3D) structure. We combined in situ x-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible spectroscopy, and first-principles calculations to study the evolution of structure and bandgap width up to 20.1 GPa. The optical band gap energy of Sb₂S₃ followed a two-step hierarchical sequence at approximately 4 and 11 GPa. We also revealed that the first step of change is mainly caused by the redistribution of band states near the conduction band maximum. The second transition is controlled by an isostructural phase transition, with collapsed layers and the formation of a higher coordinated bulky structure. The band gap reduced from 1.73 eV at ambient to 0.68 eV at 15 GPa, making it a promising thermoelectric material under high pressure.

地球上储量丰富的三硫化锑 (Sb ₂ S ₃ )，或简称锑矿，是一种很有前景的用于捕获太阳能和热通量等自然能源的材料。由弱范德华力支撑的层状结构会引起载流子传输和热膨胀的各向异性行为。在这里，我们使用应力作为机械刺激来破坏层状结构的稳定性，并观察到三维（3D）结构的结构相变。我们结合原位 X 射线衍射 (XRD)、拉曼光谱、紫外可见光谱和第一性原理计算来研究结构和带隙宽度高达 20.1 GPa 的演化。 Sb ₂ S ₃的光学带隙能量在大约4和11 GPa处遵循两步分级序列。我们还揭示了第一步变化主要是由导带最大值附近的能带态重新分布引起的。第二个转变由同构相变控制，具有塌陷层并形成更高配位的大结构。带隙从环境温度下的 1.73 eV 降低到 15 GPa 下的 0.68 eV，使其成为高压下有前途的热电材料。