Cadmium sulfide coated zinc oxide photoelectrode: Preparation and characterization

Cadmium sulfide (CdS) coated zinc oxide photoanode is prepared using two step deposition processes at relatively low temperature. The zinc oxide (ZnO) were deposited on the conducting glass substrates using doctor blade technique followed by the coating of CdS over ZnO at room temperature using chemical bath deposition method. In the present article, we are using three different types of CdS (bulk and nano forms) prepared by using chemical route. The size of the CdS was controlled using different concentration of capping agent during preparation. The samples were characterized by optical absorption, X-ray diffraction, scanning electron microscopy techniques. Further, the photoelectrochemical (PEC) performance of ZnO with CdS was tested in polysulfide electrolyte. When the CdS nanoparticles were coated on the ZnO, the optical absorption is enhanced and band edge is shifted towards visible region (from 470 to 525 nm) as compared with zinc oxide (375 nm). The device with CdS nanoparticles (type-b) shows higher photoelectrochemical (PEC) performance showing maximum short circuit current density (Jsc) of 1.51 mA/cm2 along with maximum electron life time (25.2 ms).