High resolution 3D chemical characterisation of a cadmium telluride solar cell by dynamic SIMS

Impurity elements such as chlorine and sulphur can have significant effects on the electrical performance of cadmium telluride (CdTe) solar cells. Here, the 3D distribution of such elements in a cadmium chloride treated CdTe device has been determined by high resolution dynamic SIMS, a novel technique that has not been applied to thin-film PV cells. It is found that as well as segregating to grain boundaries following treatment, chlorine also segregates to the CdS/CdTe interface. Conversely, sulphur shows a U-shaped diffusion profile. These results have potential implications for the processing thin-film CdTe devices

Analysis of MZO/CdTe photovoltaic device treated with cadmium bromide

The treatment of CdTe with a CdBr2 activation annealing step has been performed and the device characterized for its electrical, compositional and structural properties with Capacitance-Voltage, Current-Voltage, Transmission Electron Microscopy, Energy Dispersive X-ray analysis (EDX), Electron Backscattered Diffraction Analysis, photoluminescence and high spatial resolution- Secondary Ion Mass Spectrometry (nanoSIMS). NanoSIMS and EDX show the bromine segregating in the grain boundaries and also in through grain defects. This CdBr2 treated sample has a net doping density of 1.05x1014 cm-3 , an efficiency of 8.6 % with a Jsc of 23.7 mAcm-2 and Voc of 762 mV. The bandgap has been calculated to be 1.49 eV<br