The current state of CdTe/CdS solar cell development is reviewed with empha
sis on the understanding of the materials behaviour. Metallurgical and opto
electronic changes effected by the CdCl2 treatment are described with refer
ence to the CdS-CdCl2 and CdTe-CdCl2 phase diagrams. Some studies relating
to the nature, distribution and influence of important optoelectronic centr
es are described and some new results presented. These include FL, EBIC and
CL. The potential for complex interaction of processing steps in the mater
ials system is noted and key areas for future studies are highlighted. (C)
1999 Elsevier Science B.V. All rights reserved.