Annealing efect on the structural and optical behavior of ZnO:Eu3+ thin flm grown using RF magnetron sputtering technique and application to dye sensitized solar cells

Abstract

Eu-doped ZnO (ZnO:Eu3+) thin flms deposited by RF magnetron sputtering have been investigated to establish the efect of annealing on the red photoluminescence. PL spectra analysis reveal a correlation between the characteristics of the red photoluminescence and the annealing temperature, suggesting efcient energy transfer from the ZnO host to the Eu3+ ions as enhanced by the intrinsic defects levels. Five peaks corresponding to 5D0–7FJ transitions were observed and attributed to Eu3+ occupancy in the lattice sites of ZnO thin flms. As a proof of concept a dye sensitized solar cell with ZnO:Eu3+ thin flms of high optical transparency was fabricated and tested yielding a PCE of 1.33% compared to 1.19% obtained from dye sensitized solar cells (DSSC) with pristine ZnO without Eu produced indicating 11.1% efciency enhancement which could be attributed to spectral conversion by the ZnO:Eu3+.