Improved characteristics for chemically grown Cu2SnS3 promising solar absorbers through the use of TritonX-100® surfactant

In this paper, we report, for the first time, the results of the TritonX-100® surfactant assisted growth of Cu2SnS3 thin films obtained by using sol-gel spin coating method and a subsequent annealing in a sulfur atmosphere. Structural, morphological, compositional, photo-electrical investigations have been carried out. X-ray diffraction patterns of the samples matched well with the reference Cu2SnS3 pattern and indicated the polycrystalline nature of the films. Crystallite size of the films increased whereas surface roughness of the films decreased with increasing Triton-X100® content. The surface of the samples has been smoother with Triton-X100® inclusion. The photo-sensitivity of the n-Si/CTS structures has been confirmed through photo-transient current measurements. An increment was observed in the photo-induced current values of the samples with increasing Triton-X100® content and was attributed to transport of photo-induced electrons facilitated with decreasing recombination resulted from the surface enhancement of the films. Electrical conduction mechanism of the films was investigated with resistance-temperature measurements. It has been revealed that TritonX-100® surfactant assisted growth is a promising way to improve conversion efficiency of Cu2SnS3 based solar cells.