Surface passivation of Cu(In,Ga)Se 2 using atomic layer deposited Al 2O 3
Journal
Applied Physics Letters
Journal Volume
100
Journal Issue
2
Date Issued
2012
Author(s)
Abstract
With Al 2O 3 passivation on the surface of Cu(In,Ga)Se 2, the integrated photoluminescence intensity can achieve two orders of magnitude enhancement due to the reduction of surface recombination velocity. The photoluminescence intensity increases with increasing Al 2O 3 thickness from 5 nm to 50 nm. The capacitance-voltage measurement indicates negative fixed charges in the film. Based on the first principles calculations, the deposition of Al 2O 3 can only reduce about 35 of interface defect density as compared to the unpassivated Cu(In,Ga)Se 2. Therefore, the passivation effect is mainly caused by field effect where the surface carrier concentration is reduced by Coulomb repulsion. © 2012 American Institute of Physics.
Type
journal article