Improved characteristics for chemically grown Cu_2SnS_3 promising solar absorbers through the use of TritonX-100~R surfactant

摘要

In this paper, we report, for the first time, the results of the TritonX-100~R surfactant assisted growth of Cu_2SnS_3 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 Cu_2SnS_3 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-Xl00~R content. The surface of the samples has been smoother with Triton-X100~R 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~R 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~R surfactant assisted growth is a promising way to improve conversion efficiency of Cu_2SnS_3 based solar cells.