Investigation the effect of Pb incorporation on the surface characterizations of electrodeposited CdSe nanostructures

Abstract

In this paper, un- and Pb-doped CdSe nanostructures were synthesized via an electrodeposition process. The X-ray diffraction (XRD) analysis presented that the deposited CdSe nanostructures had cubic lattice with crystallite size of 10–12 nm. In addition, the obtained texture coefficient (Tc) of Pb-doped CdSe nanostructures was greater than undoped CdSe sample that presented improving the crystalline quality of CdSe nanostructures after Pb-doping. Field emission scanning electron microscopy (FESEM) images displayed that all samples have grain-like morphology with a size of ∼250–400 nm. Energy dispersive X-ray analysis (EDX) results showed that the Pb dopants was incorporated into CdSe lattice. All deposited samples showed two Photoluminescence (PL) peaks at ∼565 and ∼690 nm, which related to the deep level defects and band gap energy of CdSe lattice, respectively. The near band emission (NBE) of CdSe samples showed a blue shift after Pb-doping. Optical examinations discovered that the absorption properties of CdSe samples were more intense due to Pb-doping. The transmission and reflectance spectra of CdSe nanostructures were respectively decreased and increased after Pb-doping. Additionally, the absorption coefficient (α) of Pb-doped CdSe samples was greater than undoped CdSe sample. An absorption edge around 1.74 eV was seen in the absorption spectra of all samples that related to their band gap energies. The refractive index (n) and the extinction coefficient (k) of CdSe thin films were increased after Pb-doping. The Eg of CdSe samples was increased from 1.73 to 1.75 eV after Pb-doping. The dispersion parameters including Ed, M-1, and M-3 values of CdSe samples were increased after Pb-doping due to an improvement in their crystalline nature.