ZnO/CdS nano composite for visible light emission.

The color tunability property of nano-sized semiconducting materials for broad range visible light emission (400-700 nm) depends upon the excitation wavelength, particle size, and sintering temperature. Defect states are the most common cause of visual emission from semiconducting materials. A lot of work had been reported on visible emission due to defect centers. An attempt has been made to study the visible emission from pure ZnO, pure CdS and ZnO/CdS nano composite sintered at 600oC. Powder XRD spectra of the samples were indexed using JCPDC file No. 36-1451 confirming the hexagonal wurtzite phase. XRD pattern confirmed that CdS in ZnO did not change the hexagonal phase of ZnO. The average particle size of ZnO/CdS composite was 56.8 nm where pure ZnO had average particle size of 39 nm. The emission properties of pure ZnO, pure CdS and ZnO/CdS composite have multicolor emission due to defect center. With the introduction of CdS in ZnO, the emission properties of the ZnO/CdS nano composite were enhanced. As a result, ZnO/CdS nano composites have greater potential for optoelectronic applications than pure ZnO and CdS. [ABSTRACT FROM AUTHOR]