Type conversion and large area defects nucleation in electrodeposited CdTe solar cells
Large area (mm scale) defects nucleation has been observed in electrodeposited CdTe solar cells during the post deposition annealing process. While generally at the final stage of the process the solar cell tends to recover, exhibiting good photocurrent uniformity, in some cases these defects are still present and further annealing drastically degrades overall performances. External quantum efficiencies, variable wavelength/voltage OBIC maps, SIMS, XRD and EDX are the techniques employed to investigate the type conversion of the material and defect formation. Analysis of forward bias OBIC maps evidenced the shallow location of defects, likely located at the heterojunction, and larger background areas of different response indicated non-uniform collection profiles and local electrical junction position. Type conversion takes place starting at the back of the CdTe and progresses disorderly towards the CdS/CdTe interface. The electric junction, at annealing treatments that give optimum PV performances, is located beyond the position of the initial CdS/CdTe interface. Longer annealing times leads to the formation of photocurrent defects.
Bibliographic Reference: An oral report given at: The 17th European Photovoltaic Solar Energy Conference and Exhibition. Held in: Munich (DE), 22-26 October 2001
Record Number: 200114093 / Last updated on: 2001-11-23
Original language: en
Available languages: en