Acoustic shock wave-induced dynamic recrystallization facilitating reconstructable phase transition from zinc blende to rocksalt in cadmium telluride

Abstract

Cadmium telluride (CdTe) is a promising material for solar cells; however, its stability is compromised under high pressure and temperature, leading to structural and electronic damage, including degradation. The current study aims to investigate the behavior of CdTe under acoustic shock waves with 0.59 MPa pressure, 529 K temperature, and 1.5 Mach number by focusing on its structural, optical, and morphological properties. Techniques such as X-ray diffraction (XRD), Raman spectroscopy, UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, and field emission scanning electron microscopy (FE-SEM) were employed to analyze the material's response. The overall XRD and Raman results reveal that CdTe undergoes a reconstructable phase transition from cubic-zincblende (ZB) to cubic-rocksalt (RS) under shock wave exposure. Optical analysis revealed a reduction in the bandgap, and a shift in PL emission was observed. Morphological changes observed due to shock waves induced by dynamic recrystallization were noted after 300 shock pulses, followed by the restoration of the layered structure at 400 shock pulses. These findings highlight the reconstructable nature of phase transitions and emphasize the importance of addressing degradation pathways to improve CdTe's long-term stability and efficiency in solar cells. The observed reconstructable phase transition offers a potential method for tuning CdTe's properties under acoustic shock wave exposure.