Raman scattering assessment of point defects in kesterite semiconductors: UV resonant Raman characterization for advanced photovoltaics

Raman spectroscopy has demonstrated to be a powerful tool for Cu
₂
ZnSnSe
₄
(CZTSe) characterization, allowing the assessment of relevant parameters such as crystal quality, secondary phases and defect presence. In this work a detailed analysis of CZTSe vibrational properties using non-bandgap Raman resonance effects is performed. UV-based Raman spectroscopy is presented as a promising technique for the precise assessment of V
_Cu
and Zn
_Sn
point defects, associated with 174 and 245 cm
^-1
Raman regions. Based on these results, correlation between the peak intensity, associated with V
_cu
point defects, with the maximum value of the efficiency of the final devices is presented and discussed.