Defect and impurity diagnostics and process monitoring

The review focuses on four areas of defect and impurity diagnostics: (i) the determination of parasitic resistances, (ii) quantum efficiency analysis including light-beam-induced current measurement systems which use spectrally resolved currents to determine local recombination in solar cells, (iii) methods to determine the recombination properties in solar cell precursors and (iv) techniques suitable for the recognition of the type of impurity or defect, which is responsible for increased recombination. In general, emphasis is on those methods, which are capable of delivering spatially resolved information. The use of the specific metastability features of a defect for its identification is exemplified. In addition, carrier lifetime spectroscopy methods utilising the temperature or the injection dependence of defect recombination are outlined.