Synthesis and characterization of flower-like ZnSe nanostructured thin films by chemical bath deposition (CBD) method

Flower-like zinc selenide nanostructured thin films were successfully prepared by a chemical bath deposition method on non-conducting glass substrate in an aqueous alkaline medium using sodium selenosulphate as Se 2-ion source. The as-deposited films have been characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM), energy-dispersive X-ray analysis (EDX), optical absorption, and photoluminescence spectroscopy (PL). The XRD studies reveal that the as-deposited ZnSe thin film is nanocrystalline with a face-centered cubic phase. SEM image shows the tens to hundreds of petals are self-assembled within a single nanoflower. The direct optical band gap 'Eg' for as-deposited flower-like ZnSe thin films is found to be 2.80 eV. Room temperature PL measurement indicates that the as-deposited cubic ZnSe thin films have a near band edge (NBE) emission peaked at around 440 nm (2.81 eV) and broad weak band emission peak from 552 nm (2.24 eV) to 658 nm(1.88 eV). The strong NBE emission from the flower-like ZnSe nanostructured thin films reveals their potential as building for optoelectronic devices.