Acoustic shock wave-induced phase transition in indium selenide: tuning band gap energy for solar cell applications
Abstract
Indium selenide is a semiconducting material that has a layer-by-layer crystal structure. The present work treats indium selenide with dynamic shock waves using a semi-automatic Reddy tube at 100, 200, 300, and 400 shock pulses. The mixed phase of In4Se3 and α-In2Se3 switched to pure rhombohedral (α-In2Se3) at 100 shock pulses and remained in the same phase up to 400 shock pulses due to application of 2.0 MPa pressure and temperature of 864 K. The crystal structure transformation from orthorhombic to rhombohedral was examined using powder X-ray diffraction and Raman scattering analyses, through the formation and disappearance of peaks, the results from XRD and Raman confirm the phase transition. The morphology and optical properties of the material were investigated using scanning electron microscopy and UV-DRS. The morphology of In2Se3 is of layered shape during increasing shocks. Optical analysis revealed that the band gap of the sample increased, changing from a wide to a narrow band gap semiconducting material.