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

摘要

Cu2ZnSn(S,Se)(4) thin films were fabricated by sulfurization of the precursor evaporated from Cu2ZnSnSe4 and KF compounds. From Raman analysis, the precursor had a Cu2SnSe3 structure and transformed to Cu2ZnSn(S,Se)(4) structure after sulfurization, which was the first approach to produce Cu2ZnSn(S,Se)(4) thin films. Electron probe microanalysis revealed that the S/(Se - S) mole ratios in the sulfurized films were in the range between 0.94 and 0.99. The open circuit voltage V-oc of Cu2ZnSn(S,Se)(4) thin-film solar cells fabricated using KF improved more than that of the solar cell fabricated without KF, especially the best solar cell demonstrated with V-oc = 698 mV. (C) 2019 The Japan Society of Applied Physics