Abstract:
CdTe is a very potential absorber material for
thin film solar cell application. In this work CdTe thin films
(TF) were deposited on CdS thin films by close-spaced
sublimation (CSS) technique at different source and substrate
temperature in inert gas condition. To bring out the optimum
temperature set for CSS deposited CdTe films, several
experiments were done. The process pressure of the chamber
during deposition was maintained at 1.5 Torr in a dynamic
condition. The effects of deposition temperature on the
electrical properties of the as-deposited CdTe films were
investigated by Hall Effect measurement. The films were
deposited at 610 °C, 630 °C, 650 °C and 670 °C source
temperatures. The first three films showed p-type conductivity
while n-type conductivity appeared in the film deposited at 670
°C. The hole concentration of the as-grown p-type CdTe films
followed an upward trend with the increase of source
temperature and it reached a peak value at 650 °C. The highest
hole mobility was observed for the lowest source temperature.
However, the resistivity of the CdTe films was found increasing
with the increase of source temperature. Thus, the CdTe thin
film deposited at 650 °C showed better electrical properties for
solar cell applications.
