Compositional Disorder, Defect Evolution, and Structural Stability in ZnₓCd₁₋ₓS Solid Solutions for Optoelectronic Applications

Annotatsiya

Abstract.  ZnₓCd₁₋ₓS solid solutions are extensively employed in optoelectronic and electronic devices owing to their composition-dependent structural and electronic tunability; however, their long-term structural reliability remains insufficiently addressed. In this work, the influence of Zn incorporation on lattice evolution, defect redistribution, and aging-related structural degradation in polycrystalline ZnₓCd₁₋ₓS (0 ≤ x ≤ 0.30) solid solutions is systematically investigated. X-ray diffraction analysis confirms the formation of single-phase wurtzite structures across the entire composition range, with lattice parameters exhibiting an almost linear dependence on Zn content in accordance with Vegard’s law. Importantly, subtle deviations from ideal Vegard behavior emerge at higher Zn concentrations, indicating the onset of compositional disorder and internal lattice strain. These structural changes are correlated with accelerated defect migration and aging processes. The results identify a composition-dependent stability window, providing defect-aware guidelines for optimizing ZnCdS solid solutions in advanced optoelectronic applications.

Keywords. ZnCdS solid solutions; compositional disorder; lattice strain; Vegard’s law; defect evolution; optoelectronic materials