Optical properties of pure and doped CdS nanoparticles under solvothermal method

Abstract

The synthesis of CdS nano particles have been widely studied for their potential usage in the field of optics. The Semi conductor nanoparticles doped with transition metal ions have attracted a wide attention due to their excellent luminescent properties. The transition metal doped nano particles have different optical properties corresponding to their host counter parts. These nano particles have tremendous applications in the fabrication of optical light emitting diodes and to design a suitable window material in fabrication for solar cells. The microwave assisted solvothermal method is used to prepare the nano particles in this study. The nano structured materials of CdS were characterized by XRD and UV techniques. The size of the crystallite is determined by XRD to be 18.26 nm depending on the amount of the molar ratio of the reactants present in the sample. The nanocrystalline nature of CdS particles and the diffused pattern shows the presence of hexagonal phase in the present system. The quantum size dependent effect and the optical quality of the CdS and Mn-doped CdS are studied. The optical absorption and transmitance spectrum of the Pure and Mn-doped CdS nanocrystals are synthesized in this work. CdS is a commercially important II-VI semiconductor having wide optical band gap, rendering it a very attractive material for optical application especially in nanocrystalline form. The UV-absorption edge provides a reliable estimate of the band gap of any system. It is found that the band gap of the pure CdS nanosystem in the present study is 2.45 eV and this value is found to be larger than that of bulk CdS. This variation of the band gap may be useful to design a suitable window material in fabrication for solar cells. In optoelectronics, it finds use as light emitting diode, reflector, dielectric filter and window material.