| Abstract: | The effects of thermal annealing in conjunction with CdCl2 vapor heat treatment on the properties of CdTe/CdS thin films and devices deposited by physical vapor deposition are reported. Results are compared for three treatment variations: high‐temperature anneal only, high‐temperature anneal followed by CdCl2 vapor heat treatment and CdCl2 vapor heat treatment only. X‐ray diffraction, transmission electron microscopy and scanning electron microscopy show improved crystallographic properties of the CdTe film and reduced CdS/CdTe interdiffusion when a high‐temperature anneal is used prior to CdCl2 treatment. The CdTe/CdS solar cells fabricated using an anneal at 550°C in argon prior to the CdCl2 vapor heat treatment exhibited improved electrical characteristics compared to cells fabricated with no anneal step, yielding an open‐circuit voltage exceeding 850 mV. Copyright © 1999 John Wiley & Sons, Ltd. |
