Investigation of broad-band optical absorption and electrical properties in vacuum annealed CZTS/Ag multi-layered stack structure for plasmonic solar cell application

Abstract

As there is only a few research work carried out in thin film plasmonic Cu2ZnSnS4 (CZTS) based solar cells, it is exceedingly inspiring to advance the optical and electrical properties through incorporating Ag nanoparticles without affecting its structural properties. In this work, CZTS and Ag were stacked with the help of sequential magnetron sputtering method using RF and DC power supplies. Homogeneous distribution of Ag nanoparticles in CZTS matrix has been achieved via post deposition annealing at 500 °C. The concentration of Ag has been tailored by varying deposition time from 30 to 90 s. The morphological properties of Ag incorporated CZTS thin films has been investigated by using FE-SEM technique. The optical property of CZTS films has been enhanced by increasing the optical path length through multiple scattering due to the localized surface plasmon resonance (LSPR) of Ag nanoparticles. In Hall effect study, a gradual drop in the resistivity is observed with increasing Ag deposition time however it is within the tolerable limit of CZTS film.