Interface formation in CdTe solar cells: Nucleation of CdTe on CdS(0001) and (10(1)over-bar0)

The growth of CdTe on (0001) and (10 (1)over-bar0) surfaces of CdS was studied using low energy electron diffraction and photoelectron spectroscopy. The results indicate oriented growth of the CdTe films with a faster nucleation of CdTe on CdS(0001), explaining the preferred (111) orientation of CdTe films on polycrystalline substrates. The faster nucleation on the (0001) surface is attributed to the formation of a stable CdS(0001):Te surface termination, which is identified from surface sensitive Te 4d spectra and a 2 root 3 x 2 root 3 surface reconstruction. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.