Pressure-induced evolution of structure and electronic property of GeP

Abstract

The monoclinic semiconductor GeP is a new class of Group IV–V layered material, and it shows attractive anisotropic optical and electronic properties. In this paper, we investigate the structural and electronic evolution of layered GeP under pressure, using in situ x-ray diffraction, Raman and infrared spectra, and the density functional theory. All characterization methods reveal that the pressure causes two obvious phase changes. One isostructural transition is observed around 6 GPa. Above 21 GPa, another crystalline-to-amorphous transformation is obtained. It is worth noting that the high-pressure amorphous state can be retained at ambient conditions after the pressure is released. In addition, the pressure-induced red-shift of absorbance edge suggests its bandgap decreases with pressure. This result indicates that pressure has a significant effect on GeP. Meanwhile, it also provides a method for obtaining amorphous GeP, which is of interest to the energy storage community as it is a potential anode material for lithium-ion batteries.