Morphology and properties evolution of kesterite Cu2ZnSnS4 microfibers synthesized via electrospinning method

Solar cells and related key materials are still among the most interesting researching field. In this work, kesterite Cu2ZnSnS4 (CZTS) cross-linked fibers and dense films, which are promising candidates for active layers used in the third generation solar cells, are developed via electrospinning following sulfurization at high temperature. Morphology dependence and properties evolution are investigated for the samples obtained by sulfurization in the temperature range of 450-600 A degrees C. Samples are characterized by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, Raman and X-ray photoelectronic spectroscopy, and UV-Vis absorbance spectra. It is found that, with the sulfurization temperature increasing, morphologies develop from isolated CZTS fibers to interconnected fibers, and finally forming a sub-micron flake composed dense films, accompanying a band gap evolution from 1.49 to 1.44 eV, just by simply adjusting the solutes concentration and vulcanization parameters.