Solution processed Ag–In–S nanoparticles as light adsorber in ZnO for photovoltaic application

Nano-sized indium incorporated silver sulphide (Ag–In–S) nanocomposites were synthesized by simple wet chemical method as an electron transport layer in zinc oxide (ZnO) for high efficient photovoltaic (PV) cell. The inclusion of high conductivity indium ions in Ag$_2$S will improve the facile electron transfer and the assembled hetero-structure features the solar light harvesting in PV cell. The powder X-ray diffraction (XRD) studies confirmed the formation of indium incorporated Ag$_2$S (AIS) nanocomposites and ZnO/AIS (ZAIS) compound nanocomposites crystallizing in pure monoclinic phase and mixed wurtzite hexagonal, monoclinic and tertiary phases respectively. The wide particle size distributions in ZAIS clearly revealed the adherence of AIS nanocomposites in ZnO lattice thus, promoting the light adsorption property. In addition, the tuning of the optical bandgap covering the entire solar spectrum (UV, visible, and infra-red regions), multiple-band electron transitions and hence, promoting the fast electron transportation are effectively achieved in ZAIS compound nanocomposites. With this simple positive approach, the PV cell efficiency is pushed forward with the In$^{3+}$ metal ion incorporation however; enhanced, enriched solar cell efficiency can be later tuned up with the detailed optimization studies.