Synthesis and Characterization of Cu2ZnSnS4 and its Nanocomposites for Solar Photovoltaic and Photocatalytic Applications

Abstract

CZTS (copper zinc tin sulfide or Cu2ZnSnS4) is a p-type semiconductor material with high newlineabsorption coefficient (104 newlinecm-1 newline) and tunable bandgap (1.4 1.6 eV). It is combination of newlineearth-abundant and non-toxic elements. It can be easily fabricated using cost-effective newlineprocess. Additionally, this material has been the focus of research for over two decades due newlineto its remarkable oxidation ability in photocatalysis and promising environmentally benign newlineabsorber layer in the solar cell. In this work, we prepared CZTS nanoparticles (NPs) and their newlinecomposites and CZTS thin films for photocatalytic and photovoltaic applications. newlineIn the present study CZTS nanoparticles (NPs) and CZTS-multiwalled carbon nanotube newline(MWCNT) (CZTS-MWCNT) heterostructured nanocomposites (NCs) were synthesized by a newlinelow-cost hydrothermal method. The CZTS NPs and CZTS-MWCNT NCs of varying newlineMWCNT contents (3 wt%, 6 wt% and 9 wt%) were characterized by XRD, SEM, TEM, newlineRaman and UV-Vis spectroscopy. X-ray diffraction studies revealed that CZTS samples are newlinein kesterite phase and the peaks in the diffraction pattern are in accordance with JCPDS no. newline26 0575. The diffraction peak corresponding to MWCNT was not clearly observed in the newlinediffraction pattern of CZTS-MWCNT NCs due to their low concentration. Interestingly, the newlinediffraction peak intensity increased compared to CZTS NPs, indicating that the addition of newlineMWCNTs increased crystallinity. The TEM image confirmed that the CZTS NPs are newlineanchored to MWCNTs. The BET surface area of CZTS NPs was 12.59 m2 newline/g, which is newlineslightly lower than the 13.94 m2 newline/g observed for CZTS-6 wt% MWCNT NCs, indicating that newlineMWCNTs increase surface area due to enhanced pore size distribution and pore volume. The newlinebandgaps of CZTS NPs, CZTS-3 wt% MWCNT NCs, CZTS-6 wt% MWCNT NCs, and newlineCZTS-9 wt% MWCNT NCs are 1.65 eV, 1.58 eV, 1.4 eV, and 1.51 eV, respectively. The newlineCZTS-6 wt% MWCNT NCs with an optimum bandgap (1.4 eV) can absorbed more number newlineof photons when exposed to solar radiation, leading to an increase in photoc