Fabrication of Cu sub(2ZnSnS) sub(4) films by sulfurization of Cu/ZnSn/Cu precursor layers in sulfur atmosphere for solar cells

• Published in: Solar energy materials and solar cells Vol. 95; no. 12; pp. 3216 - 3221
• Main Authors: Chalapathy, RBV, Jung, Gwang Sun, Ahn, Byung Tae
• Format: Journal Article
• Language: English
• Published: 01.12.2011
• ISSN: 0927-0248
• DOI: 10.1016/j.solmat.2011.07.017

Cu sub(2ZnSnS) sub(4) (CZTS) absorbers were grown by sulfurization of Cu/ZnSn/Cu precursors in sulfur atmosphere. The reaction mechanism of CZTS formation from the precursor was analyzed using XRD and Raman spectroscopy. The films with a single phase CZTS were formed at 560 and 580 degree C by sulfurization for 30 min. The film grown at 560 degree C showed bi-layer morphology with grooved large grains on the top and dense small grains near the bottom of the film. On the other hand, the film grown at 580 degree C showed large grains with grooves that are extended from surface top to bottom of the film. The solar cell fabricated with the CZTS film grown at 560 degree C showed the best conversion efficiency of 4.59% for 0.44 cm super(2 with V) sub(o)c=0.545 V, J sub(sc=15.44 mA/cm) super(2), and FF=54.6. We found that further improvement of the microstructure of CZTS films can increase the efficiency of CZTS solar cells.