In-situ antimony doping of CdTe

Abstract

The effect of in-situ Antimony (Sb) doping on polycrystalline Cadmium Telluride (CdTe) deposited by Elemental Vapor Transport (EVT) is investigated. The presence of Sb in the film is verified by SIMS measurements. The film structures were studied by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) measurements. The Sb doped CdTe films were fabricated into solar cells and characterized by standard Current-Voltage (JV) and Spectral Response (SR) measurements. The performance of the cells did not reach the state-of-the-art level, however, VOC's up to 760 mV were observed without any post deposition Cu or CdCl2 heat treatment. Capacitance-Voltage (CV) measurements indicated a change in the p-type doping concentration (as high as 1016 cm-3) as a function of gas phase Cd/Te ratio and Sb concentration. 1-Photon TRPL measurements showed minority carrier lifetime, τ > 1ns for the films with the highest doping.