EBIC and luminescence mapping of CdTe/CdS solar cells

The roles of EBIC, OBIC (LBIC), spatially resolved spectral response and cathodoluminescence in determining the influence of grain boundaries in the CdTe/CdS solar cell are critically reviewed. Conventional use of EBIC in the determination of junction position and Le in thin films is assessed. Direct evidence of grain boundary passivation from front-wall (illumination geometry) OBIC and EBIC is described. The use of non-standard injection-dependent EBIC to probe near grain boundary doping, and a model of grain boundary passivation is outlined. New results of the use of cathodoluminescence microscopy to probe individual grains are presented and discussed with regard to passivation.