Photoelectrochemical cells (PECs) of ZnO/CdSe decorated with a charge separating SnO2 nanoparticles (NPs) layer of various thicknesses are prepared and characterized by using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), UV-visible absorption, energy dispersive X-ray analysis spectroscopy (EDX) and incident photon-to-current conversion efficiency (IPCE) measurements. A uniform coverage of the SnO2 NPs layer over ZnO/CdSe electrode surface is evidenced. The EDX elemental mapping analysis of the ZnO/CdSe/SnO2 PECs demonstrates the presence of Sn and O over the surface. A remarkable improvement in the light harvesting efficiency confirmed from the IPCE measurement, supports an enhancement in current density in the current density–voltage measurement due to increased electron transport and smaller charge recombination. Moreover, these observations are corroborated with the EIS measurement as a cell with SnO2 reveals a reduced charge transfer resistance due to which the power conversion efficiency is increased from 2.20 to 3.41% i.e. 55% compared to the pristine ZnO/CdSe PEC.
|Number of pages
|Journal of the Chemical Society. Dalton Transactions
|Published - 20 Aug 2013