Strain Effects on the Electronic and Optical Properties of Kesterite Cu2ZnGeX4 (X = S, Se): First-Principles Study

Nanomaterials

Maykel Courel¹  Miguel Ojeda¹  Mohamed Kria²  Jawad El Hamdaoui²  Mohamed El-Yadri²  El Mustapha Feddi²  Mohamed Farkous²  Laura M. Pérez³  David Laroze³  Anton Tiutiunnyk³ 

[1] Centro Universitario de los Valles (CUValles), Universidad de Guadalajara, Ameca 46600, Mexico;Group of Optoelectronic of Semiconductors and Nanomaterials, ENSAM, Mohammed V University in Rabat, Rabat 10100, Morocco;Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7 D, Arica 1000000, Chile;

关键词: kesterite;    CZGS;    CZGSe;    strain engineering;    optical properties;   

DOI  :  10.3390/nano11102692

来源: DOAJ

【 摘 要 】

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 Cu${}_2$ZnGeS${}_4$ and Cu${}_2$ZnGeSe${}_4$. 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 Cu${}_2$ZnGeX${}_4$(X = S, Se) in the field of photovoltaic devices.

【 授权许可】

Unknown