Paste consisting of $CdS_{1-x}Te_x$ powder, 5 w/o $CdCl_2$ as a sintering aid and appropriate amount of propylene glycol have been coated on glass substrates, and were sintered in the temperature range from 625℃ to 700℃ to find phase boundary of the binary system, energy band gap and electrical properties of the semiconductors.
The solubility of Te in CdS at 625℃ is 0.1 and the energy gap decreases from 2.43eV for CdS(x=0) to 1.87eV for $CdS_{0.9}Te_{0.1}$ (x=0.1). The solubility of S in CdTe is 0.16 and the energy band gap decreases from 1.46eV for CdTe (x=1) to 1.42eV for $CdS_{0.14}Te_{0.86}$ (x=0.86).
The misbility gap boundaries of binary system at 700℃ are 0.12 and 0.84.
Both the carrier concentration and mobility of the alloy semiconductors decreases with increasing Te content.