Experimental and theoretical investigation of pure and (Co,Sr) co-doped CdS system for optoelectronics applications: A quantitative comparison

This work reports an experimental and theoretical investigation of pure, Sr, and (Sr,Co) co-doped CdS systems. Pure and co-doped CdS nanostructure thin films were grown with varying Co doping concentrations by sol-gel spin coating method. X-ray diffractograms of the films reveal that the films grow along (002) plane and the crystallites sizes were about similar to 3-6 nm. The band gaps of the films were obtained in order of 2.30-2.48 eV and a blue shift in the band gap with co-doping was observed in comparison with Sr:CdS system. In addition, pure and co-doped CdS system were also investigated via density functional theory. Initially, pure and co-doped CdS systems were optimized using WIEN2k software based on density functional theory. The calculated optical properties and band gap reveal a close agreement with the experimental results. The (Sr,Co) co-doped CdS shows the spin polarization effect on the valence band which makes this materials suitable for optoelectronics and spintronics applications.

Automated summary

This work investigates pure, Sr, and (Sr,Co) co-doped CdS systems through experimental and theoretical methods. Thin films of pure and co-doped CdS nanostructures were grown using sol-gel spin coating, with varying Co doping concentrations. X-ray diffractograms showed growth along the (002) plane and crystallite sizes of approximately 3-6 nm. The films exhibited band gaps of 2.30-2.48 eV, with a blue shift observed in the co-doped CdS compared to the Sr:CdS system. Density functional theory calculations revealed excellent agreement with the experimental results, and the (Sr,Co) co-doped CdS demonstrated spin polarization effects on the valence band, making it suitable for optoelectronics and spintronics applications.