Influence of Cu doping on optical properties of (Cd–Zn)S nanocrystalline thin films: a review

Sulfide based phosphors such as CdS and ZnS have been potential candidates for their promising applications in various optoelectronic applications. However, much of these applications demand a reproducible, reliable and controllable synthesis method that takes special care of their functional properties. It is well established that (Cd–Zn)S films possess properties between those of CdS and ZnS. Since, their addition produces a common lattice in which band structure has a larger band-gap than CdS, it makes the material more attractive for fabricating display devices. With Cu doping, it can be used as a green and blue emitting active layer. Here in, we present a critical review on the structural and optical properties of pure and Cu-doped (Cd–Zn)S films prepared by different techniques. The effect of Cu doping has been reviewed in the light of dependence of structural and optical properties on various parameters, such as Cd/Zn ratio, molar concentration, pH variation, temperature, capping legends and deposition time. The possibility of these films to be used for electrical and thermo-electrical applications is also discussed.