Pastes consisting of $Cd_{0.9}Zn_{0.1}S_{1-y}Te_y$ powder, 20wt\% of $CdCl_2$ as a sintering aid and appropriate amount of propylene glycol(P.G.) have been coated on glass substrates and sintered at $625\circ \!C$ for 1hr or 6hr to make S-rich solid solution. Energy band gap and electrical properties of the sintered films have been investigated by measuring optical transmission spectra and Hall voltages. Scanning electron microscope(SEM) and ion coupled plasmas(ICP) emission spectroscope technique were used to analyze microstructure and composition of the sintered films. Solubility was determined by measuring lattice parameters with X-ray diffractometer.
The grain size decreases, the pore fraction increases and the shape of grains becomes rounded with increasing Te content resulting in the reduction of the optical transmittance of the sintered film. Zn and Te contents of the sintered films were less than half of the initial contents. The energy band gap of the sintered $Cd_{0.97}Zn_{0.03}S_{1-y}Te_y$ films decreases with increasing Te content up to 0.05 and remains constant with further increasing Te content. The solubility of Te in $Cd_{0.97}Zn_{0.03}S$ at $625\circ \!C$ is 0.05. The energy band gap of $Cd_{0.97}Zn_{0.03}S_{0.95}Te_{0.05}$ is 2.0eV. Electrical resistivity of the films sintered for 1hr decreases with increasing Te content up to 0.025 and increases with further increasing Te content and that of the films sintered for 6hr increases with increasing Te content.
For Te-rich solid solution, pastes consisting of $(1-y)CdTe+yCd_{0.9}Zn_{0.1}S$ powder, 4.5wt\% of $CdCl_2$ and appropriate amount of P.G. have been coated on glass substrates and sintered at $625\circ \!C$ for 1hr. The energy band gap of $(1-y)CdTe+yCd_{0.9}Zn_{0.1}S$ films decreases with increasing the value of y up to 0.1 and remains constant with further increasing y. The solubility of S in $Cd_{0.988}Zn_{0.012}Te$ is 0.12. The energy band gap of $Cd_{0.988}Zn_{0.012}S_{0.12}Te_{0.88}$ film is 1.41eV.
