Effects of D+ implantation on the properties of CdS/CIGS and ZnO/CdS/CIGS heterostructures

Cu(InGa)Se₂ thin films with a Mo back contact and coated with a 30 nm of CdS layer, were implanted with doses from 10¹⁴ to 10¹⁶ cm^-2 of 2.5 keV D⁺ at room temperature. Implanted and nonimplanted area were characterised using low temperature photoluminescence (PL). ZnO dot-contacts were then deposited by RF sputtering to produce ZnO/CdS/CIGS/Mo photovoltaic devices and the spectral photo-response measured. A broad band (A) at 1.07 eV dominated the PL spectra from the nonimplanted material. Implantation of D⁺ generated four new transitions in the PL spectra: three low energy peaks and a new peak at 1.1 eV. A considerable reduction in the blue shift (j-shift) of the main band with increasing excitation power followed implantation and was attributed to passivation effects of D⁺. Annealing at 100°C for 30 min increased both the PL intensity and j-shift although the effect of passivation by D⁺ an the j-shift was only observed for the highest implanted dose following anneal