CdSxSe1x

CdSxSe1-x is a solid solution of cadmium sulfide (CdS) and cadmium selenide (CdSe), in which x denotes the mole fraction of sulfur and controls composition from pure CdSe (x=0) to pure CdS (x=1). The alloy can be formed as powders, thin films, or semiconductor nanocrystals.

The crystal structure of CdSxSe1-x follows the same motifs as its end members, most commonly the wurtzite or zinc blende forms. The lattice parameter changes approximately linearly with composition (Vegard's law), though a small bowing parameter often introduces nonlinearity in both lattice spacing and band structure.

Electronic properties, particularly the bandgap, are tunable by composition. Eg ranges roughly from 1.74 eV for CdSe-rich compositions to about 2.42 eV for CdS-rich compositions, with intermediate values depending on x and the crystal phase. Bowing effects can alter the precise dependence.

In nanostructures, quantum confinement further shifts optical properties, allowing emission and absorption to be tuned by both composition and particle size. CdSxSe1-x alloys are therefore of interest for solar-energy devices, light-emitting diodes, and photodetectors.

Synthesis methods include colloidal chemistry, chemical bath deposition, and solvothermal routes, enabling controlled composition and nanocrystal size. The material inherits safety considerations from cadmium compounds, which are toxic; proper handling and disposal are required.