Strain effects on the electronic and optical properties of kesterite Cu<inf>2</inf> ZnGeX<inf>4</inf> (X = S, Se): First-principles study
Abstract:
Following the chronological stages of calculations imposed by the WIEN2K code, we have performed a series of density functional theory calculations, from which we were able to study the effect of strain on the kesterite structures for two quaternary semiconductor compounds Cu2 ZnGeS4 and Cu2 ZnGeSe4. Remarkable changes were found in the electronic and optical properties of these two materials during the application of biaxial strain. Indeed, the band gap energy of both materials decreases from the equilibrium state, and the applied strain is more pronounced. The main optical features are also related to the applied strain. Notably, we found that the energies of the peaks present in the dielectric function spectra are slightly shifted towards low energies with strain, leading to significant refraction and extinction index responses. The obtained results can be used to reinforce the candidature of Cu2 ZnGeX4 (X = S, Se) in the field of photovoltaic devices.
Año de publicación:
2021
Keywords:
- Kesterite
- CZGSe
- Strain engineering
- CZGS
- optical properties
Fuente:
Tipo de documento:
Article
Estado:
Acceso abierto
Áreas de conocimiento:
- Ciencia de materiales
- Ciencia de materiales
Áreas temáticas:
- Química física
- Química inorgánica
- Física aplicada