A Study on Hydrothermal Grown CdS Nanospheres: Effects of Cd/S Molar Ratio

Authors : Salih YILMAZ, Murat TOMAKIN, Ahmet UNVERDI, Abdulaziz ABOGHALON

Pages : 1271-1281

Doi:10.35378/gujs.513525

View : 16 | Download : 10

Publication Date : 2019-12-01

Article Type : Research Paper

Abstract :The study reports the influences of altering of Cd/S molar ratio on some physical properties of hydrothermal grown CdS nanospheres. Cd/S molar ratios were chosen as 1:0.5, 1:1, 1:2, 1:3 and 1:4 in the stock solution. X-ray diffraction insert ignore into journalissuearticles values(XRD); data showed the occurrence of nano-amorphous CdS structure. Scanning electron microscopy insert ignore into journalissuearticles values(SEM); conclusions illustrated that increasing Cd/S molar ratio up to 1:3 caused a growth in the sphere size whereas further rising of Cd/S molar ratio led to smaller sphere size. The presence of Cd and S atoms in CdS structure was approved by Energy dispersive x-ray spectroscopy insert ignore into journalissuearticles values(EDS); analysis. Optimum transparency was found by Cd/S molar ratio of 1:3. Band gap scores of CdS nanospheres were determined to be above 2.60 eV that was bigger than bulk CdS insert ignore into journalissuearticles values(2.42 eV); because of quantum confinement effect. Photoluminescence insert ignore into journalissuearticles values(PL); results showed that a gradual decrease in each peak was attained upon increasing Cd/S molar ratio, which could be due to the formation non-radiative recombination phenomenon. Electrical data demonstrated that CdS nanosphere having Cd/S molar ratio of 1:1 exhibited the best carrier density insert ignore into journalissuearticles values(1.48 ´ 1015cm-3); and resistivity insert ignore into journalissuearticles values(1.27 ´ 103 Ω.cm); values. Thus, it can be deduced that Cd/S molar ratio of 1:3 was obtained to be optimum one since it possesses both bigger sphere size and better transparency, facilitating the effective use of CdS nanospheres in the solar cells. 
Keywords : CdS nanospheres, Hydrothermal method, SEM, Aptical properties, Electrical data