Structural, Optical and Optoelectrical Study of ZnS Nanoparticles by Varying Reducing Agent in Chemical Reduction Route

Abstract

In this work we report on the growth of ZnS semiconductor nanocrystals with different ratio of reducing agent using chemical reduction route in THF medium. Reducing agent takes an important role in the growth of nanoparticles as it determines the reaction rate in the formation of ZnS nanoparticle. With increased amounts of sodium borohydride as a reducing agent, the sizes of the nanoparticles are decreased. The samples are characterized using XRD, electron diffraction, electron micrograph, EDAX, optical absorption, photoluminescence techniques. XRD and TEM shows that particle size is reduced with increase of reducing agent ratio. Optical absorption study shows that band gap increases with decrease of particle size. Photoluminescence study shows that there is band edge luminescence as well as luminescence from surface states. Photoconductivity and conductivity of the films composed of ZnS nanoparticles are studied. Relaxation time is measured and is found to be dependent on the size of the nanoparticle.