High-resolution local current measurement of CdTe solar cells

We investigate local electronic properties of CdTe solar cells using electron beam to excite electron-hole pairs and evaluate spatially resolved photocurrent characteristics. Standard semiconductor processes were used to fabricate Ohmic metal contacts on the surface of p-type CdTe / n-type CdS device extracted from a commercial solar panel. An ion milling process was used to prepare cross-sections of the devices. Local injection of carriers was controlled by an acceleration voltage of electron beam (1 kV to 30 kV) in a scanning electron microscope, and the results were correlated with the local morphology, microstructure, and chemical composition of the devices.