Investigation the influence of Fe (III) doping in Cu2ZnSnS4 semiconductor: Structural, optical and magnetic properties

摘要

Recently, quaternary Cu2ZnSnS4 (CZTS) semiconductor has been garnering attention in CZTS thin film solar cells. In order to improve the physical properties of CZTS semiconductor which in turn enhancing the conversion efficiency of CZTS thin film solar cells, Fe+3 has been incorporated into CZTS semiconductor using the solvothermal method. The experimental results of effecting Fe+3 showed that the Fe+3 had stronger hybridization and more effective on energy storage than Fe+2 thus it's more convenient than Fe+2. XRD pattern revealed the crystal structure was high crystallinity and low distortion. Raman analysis indicated the structural transition from kesterite cu(2)ZnSnS(4) to stannite Cu2FeSnS4 occurred in the Cu-2(Zn1-xFex)SnS4 samples with Fe3+ content (x) in the range of 0.75-1. UV-Vis absorption spectrum showed the Cu2FeSnS4 semiconductor had a new opto-magnetic property. Where the magnetic energy resulted from incorporating Fe+3 in Cu2ZnSnS4 has been storage and distributed in abroad absorption band in UV-vis ranges. Also, increasing Fe+3 content led to a decrease in the direct bandgap in the ranges of 1.54 eV to 1.27 eV. FE-SEM showed that the shape of particles has been changed from sphere like to rod-like and then to sheet-like particles which are strongly related to the magnetic exchange energy. The iron-containing samples were superparamagnetic materials, thus at the low and high field, all samples showed no hysteresis area and hence no coercivity and no remanence. This showing that incorporating Fe3+ atoms into CZTS semiconductor may be well suitable for fabricating it as an absorber layer in CZTS thin film solar cell.