Surface passivation of crystalline silicon solar cells by Cr:ZnO coating layers

Abstract

Abstract In this paper, ZnO thin films with and without Cr doping were synthesized using a simple co-precipitation approach and coated on silicon substrates using spin-coating. The study assessed how the introduction of Cr doping content influenced both the structural and opto-electronic characteristics of the films. Analysis of crystal structure and surface morphology was conducted through techniques such as atomic force microscopy (AFM) and X-ray diffraction (XRD). Additionally, the evaluation of surface passivation and reflectivity in both Cr-doped and undoped ZnO films was performed using methods involving FTIR and photoconductance. Notably, Chromium doping led to a remarkable increase in the effective minority carrier lifetime, which rose from 1.5 to 88 μs at a minority carrier density (n) of 1014 cm-3. Moreover, the reflectivity at λ= 500 nm decreased from 30% to around 7% upon coating silicon with Cr-doped ZnO.