The influence of CdTe growth ambient on MOCVD grown CdS/CdTe photovoltaic cells

CdS/CdTe photovoltaic cells have been grown by MOCVD (metal-organic chemica l vapour deposition) with a range of VI/II ratios in the CdTe reactant mixt ure. All CdTe layers were highly doped with As (approx. 2 x 10(18) atoms/cm (3)) to ensure p-type conductivity. Cell characteristics were measured in t he as-grown state, without ex-situ CdCl2 or annealing treatments. The VI/II ratio, determined by the ratio of the organometallic concentrations, stron gly affects cell performance, with a peak in photocurrent occurring at Te/C d at approximately 0.6. An increase in growth temperature from 320 to 350 d egreesC more than doubles the efficiency at this VI/II ratio. An exponentia l-type relationship between the photocurrent and series resistance is appar ent at each growth temperature. (C) 2001 Published by Elsevier Science B.V. All rights reserved.