Effects of multi-defects at metal/semiconductor interfaces on electrical properties and their influence on stability and lifetime of thin film solar cells

This communication analyses some of the results observed for metal/n-CdTe interfaces in the mid-1980s, which could not be interpreted at that time. These observations are analysed on the basis of new understanding using a new model proposed for CdS/CdTe thin film solar cells. The observed behaviour of current-voltage characteristics of electrical contacts to n-CdTe under electrical and illumination stresses are explained and the effects of these changes on CdS/CdTe solar cells are discussed. Future research directions for the development of CdS/CdTe solar cells are proposed and the way forward for improvement of stability and lifetime of solar cells is suggested. A summary of recent electrical contact work on metal/Cu(InGa)(SSe)2 interfaces is also presented and similar behaviour is reported.