Characterization of Cu2ZnSnSe4 solar cells prepared from electrochemically co-deposited Cu–Zn–Sn alloy

• Published in: Solar energy materials and solar cells 2015-01, Vol.132, p.21-28
• Main Authors: Kondrotas, R., Juškėnas, R., Naujokaitis, A., Selskis, A., Giraitis, R., Mockus, Z., Kanapeckaitė, S., Niaura, G., Xie, H., Sánchez, Y., Saucedo, E.
• Format: Article
• Language: English
• Subjects: Cross-section; CZTSe; Electrochemical co-deposition; Selenization; Solar cells
• ISSN: 0927-0248; 1879-3398
• DOI: 10.1016/j.solmat.2014.08.010

Cu–Zn–Sn (CZT) precursors for Cu2ZnSnSe4 (CZTSe) solar cell were prepared by electrochemical co-deposition method with different metals composition. CZT precursors were preliminary annealed in three different atmospheres in order to obtain homogenous, without pores Cu–Zn–Sn layers. A high crystalline quality CZTSe absorber was synthesised as has been determined by X-ray diffraction and Raman spectroscopy methods. CZTSe based solar cells were fabricated and champion cell demonstrated 2.7% efficiency and reached as high as 70% of external quantum efficiency. Scanning electron microscope investigations of CZTSe solar cells cross-section revealed that Mo/CZTSe interface exhibits large voids and local delamination from Mo layer. The back contact issues are detrimental to solar cell performance reducing shunt resistance and open circuit voltage. •CuZnSn precursors were preliminary annealed under three different atmospheres.•CZTSe was fabricated from CuZnSn precursor with different elemental composition.•Cross section of Cu–Zn–Sn and CZTSe layers were prepared by focus ion beam method.•CZTSe solar cell were fabricated and optoelectronic parameters were investigated.•Champion cell demonstrated 2,7% efficiency and EQE reached as high as 70%.