Characterisation of in Situ Arsenic Doped Cadmium Sulphide/Cadmium Telluride Solar Cells Using Laser Beam Induced Current (LBIC)

23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2596-2598
This paper discusses the application and results of Laser Beam Induced Current (LBIC) characterisation of CdTe/CdS solar cells with different arsenic concentrations ranging from 1×1017 to 2×1019 atoms cm-3. Results are presented on the effect of arsenic concentration in the bulk in terms of the induced current, uniformity and lateral collection. A plot of the arsenic concentration versus LBIC response and device efficiency results in a maximum in induced current and device efficiency at 2×1018 atoms cm-3. Each device scan shows microscopic variations in the induced current with new linear “furrow defects” features that are too large to correlate directly to the grain boundaries. The nature of these furrow defects is discussed in terms of spatial variations in alloying and arsenic doping.