Improvement of hetero-interface engineering by partial substitution of Zn in Cu2ZnSnS4-based solar cells Charif Tamin, Denis Chaumont, Olivier Heintz, Aymeric Leray and Mohamed Adnane EPJ Photovolt., 13 (2022) 24 Published online: 18 October 2022 DOI: 10.1051/epjpv/2022022