The optical study of transmission T(λ) and reflection
R(λ) spectra has enabled us to determine compounds that possess gaps close to
1.5 eV. The conditions for preparation of a ternary compound whose gap is
1.48 eV have been used to create a Pb1−xCdxS-n/Si-p
heterojunction. The heterojunction thus obtained presented a low yield
(0.5%), as determined from the study of the J–V characteristic. In order to
improve its efficiency, we have studied the effect of thermal treatment on
the prepared heterojunction. X-ray diffraction has been used to determine
the variation in the crystalline parameter and the ratio of cadmium in the
Pb1−xCdxS compound, and the dependence of its gap on the
cadmium concentration. We have also used the C–V technique to determine the
average concentration of impurities in the Pb1−xCdxS compound.