Opto-electronic properties and solar cell efficiency modelling of Cu2ZnXS4 (X = Sn, Ge, Si) kesterites

In this work, first-principles calculations of Cu2ZnSnS4, Cu2ZnGeS4 and Cu2ZnSiS4 are performed to highlight the impact of the cationic substitution on the structural, electronic and optical properties of kesterite compounds. Direct bandgaps are reported with values of 1.32, 1.89 and 3.06 eV respectively for Cu2ZnSnS4, Cu2ZnGeS4 and Cu2ZnSiS4 and absorption coefficients of the order of 10(4) cm(-1) are obtained, indicating the applicability of these materials as absorber layer for solar cell applications. In the second part of this study, ab initio results are used as input data to model the electrical power conversion efficiency of kesterite-based solar cells. In that perspective, we used an improved version of the Shockley-Queisser model including non-radiative recombination via an external parameter defined as the internal quantum efficiency. Based on predicted optimal absorber layer thicknesses, the variation of the solar cell maximal efficiency is studied as a function of the non-radiative recombination rate. Maximal efficiencies of 25.71%, 19.85% and 3.10% are reported respectively for Cu2ZnSnS4, Cu2ZnGeS4 and Cu2ZnSiS4 for vanishing non-radiative recombination rate. Using an internal quantum efficiency value providing experimentally comparable VOC

Jaar van publicatie:2021

Trefwoorden:kesterite, S compounds, first-principles calculations, Sn cation substitution, opto-electronic, efficiency modelling

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:3

Auteurs:International

Authors from:Government, Higher Education, Private

Toegankelijkheid:Open