S. Duke et al., CHARACTERIZATION OF IN-SITU THERMALLY EVAPORATED CDS CDTE THIN-FILM SOLAR-CELLS WITH NI-P BACK CONTACTS/, Journal of crystal growth, 159(1-4), 1996, pp. 916-919
CdS/CdTe thin film solar cells have been produced using the in-situ th
ermal evaporation of CdS followed by CdTe onto SnO2 coated glass subst
rates and a novel contact material, Ni-P, used to make contact to the
p-CdTe. The specific contact resistivity of this contact to p-CdTe was
found to be reduced to 0.08-0.01 Ohm . cm(2) for an optimum annealing
temperature of 250 degrees C, the behaviour corresponding to a reduct
ion in the percent of P in the Ni-P contact and an increase in photocu
rrent for illuminated CdS/CdTe/Ni-P solar cells. Photocapacitance data
for such solar cells depended strongly on whether or not the devices
had been given a CdCl2 heat treatment prior to contact formation, the
heat treatment eliminating deep states within the CdTe. Shallow levels
with depths of 0.10, 0.21 and 0.38 eV were observed for the untreated
samples and shallow levels with depths of 0.04, 0.08, 0.15 and 0.21 e
V for the CdCl2 treated samples.