Quantum dot sensitized zno nanorods Based solar cell

Abstract

ZnO nanorods have been prepared by two-step simple chemical method. newlineFirst step is seed layer preparation and the second step is growth of ZnO newlinenanorods. The ZnO seed layer has been prepared by sol gel dip coating method. newlineThe field emission scanning electron microscope images of the prepared ZnO newlinesample shows the presence of vertically aligned ZnO nanorods. The X-ray newlinediffraction pattern of ZnO nanorods shows the presence of sharp peaks that newlineindicates that the film is crystalline in nature. The grain size value is found to be newline24 nm for ZnO nanorods and it has been calculated by using Scherrerand#8223;s equation. newlineThe absorption spectra shows absorption edge at 365 nm for ZnO nanorods thin newlinefilm and this is attributed to the UV absorption of the material. The newlinephotoluminescence spectra shows four peaks present at 395, 419, 488, 533 nm. newlineThe photoluminescence peak at 419 nm corresponds to zinc vacancy and 488 nm newlinepeak corresponds to oxygen vacancy and interstitial oxygen. newlineCdS quantum dots and CdS quantum dots sensitized ZnO nanorods have newlinebeen prepared by SILAR (successive ionic layer adsorption and reaction) newlinemethod. The grain size of CdS quantum dot based films have been calculated newlineusing Scherrerand#8223;s equation and the value was found to be 2 nm. The absorption newlineedge of the CdS quantum dots is present at 460 nm. The optical band gap of the newlineprepared CdS quantum dots has been found to be 2.5 eV. Field emission newlinescanning electron microscope image of CdS quantum dots sensitized ZnO newlinenanorods shows the presence of vertically aligned ZnO nanorods with hexagonal newlineshape which have grown uniformly and the CdS quantum dots are seen above newlinethe ZnO nanorods. Energy dispersive X-ray analysis (EDX) pattern of CdS newlinesensitized ZnO nanorods shows that the prepared film contains the elements Zn, newlineO, Cd and S. TEM image of the CdS sensitized ZnO film indicates the presence newlineof ZnO nanorods with CdS quantum dots over the ZnO nanorods newline