The influence of high-temperature annealing of electrochemically deposited Cu-Zn-Sn layers on the composition and structure of kesterite films — absorbing layers of solar cells

Resumo

Cu_1−δZn_2−xSn_xS₄ (CZTS) films were prepared by sequential electrochemical deposition on different supports (Ta, Ti, Mo, and glass—Mo). The samples obtained using preliminary annealing in inert nitrogen atmosphere contained a secondary intermetallic phase Cu₆Sn₅ that did not disappear upon subsequent annealing in reactive sulfur atmosphere at 550 °C for 30 min. The CZTS films prepared without preliminary annealing in inert nitrogen atmosphere contained a minimum amount of secondary phases after the sulfurization step. The samples prepared were characterized by a photovoltaically suitable band gap of 1.5 eV and p-type conductivity.