Fabrication of Cu_2ZnSn(S, Se)_4 thin-film solar cells by sulfurization using Cu_2ZnSnSe_4, NaF and KF compounds

摘要

Cu2ZnSn(S, Se)(4) thin films were fabricated by sulfurization of the precursor evaporated from Cu2ZnSnSe4, NaF and KF compounds, From Raman analysis, the precursor had mixed Cu2SnSe3 and Cu2ZnSnSe4 structure with no NaF, and the Cu2SnSe3 structure became dominant by adding NaF. After sulfurization, Cu2ZnSn(S, Se)(4) was formed in all samples, even if the precursors had different structures. Electron probe microanalysis revealed that the S/(Se + S) molar ratios in the sulfurized films were in the range between 0,95 and 0.97, The open-circuit voltage V-oc and the short-circuit current density J(sc) of Cu2ZnSn(S, Se)(4) thin-film solar cells fabricated using NaF and KF improved more than one of the solar cells fabricated using only KF. (C) 2020 The Japan Society of Applied Physics