Effect of (SbS) addition on the physical properties of quaternary (CdTe)_(100-x)(SbS)_x (0 ≤x≤ 28 at. %) glasses and band gap engineering

摘要

Effects of incorporating (SbS) in the quaternary (CdTe)_(100-x)(SbS)_x (x = 0, 8, 16, 20 and 28 at. %) glasses on different physico-chemical properties were investigated using the chemical bond approach. In addition to the estimation of the coordination number, constraint number (Ns), heat of atomization (H_s), cohesive energy and lone pair electrons, one presents theoretically the band gap estimation as well as the valence band (E_(VB)) and conduction band (E_(CB)) positions. The theoretical estimations of band gap are in good agreement with the previously published experimental results, and all compounds have their band gap in the infrared range (from 1.58 to 1.36 eV). Therefore, these materials may be used as an optical absorber in the wavelength range between 0.784 and 0.911 μm. This indicates that the studied compositions could be used for the development of new-generation infrared systems as well as for solar cell devices. Furthermore, the increase of (SbS) content decreases the network rigidity, but due to the decrease in the excess of Cd-Cd, one found, in contrary, an increase in the cohesive energy of the system.