Post modification of perovskite sensitized solar cells by aluminum oxide for enhanced performance

Abstract

The method of post-modification by aluminum oxide was successfully introduced into perovskite sensitized solar cells with a liquid electrolyte. Post-modification by Al₂O₃ could both protect the perovskite sensitizer from corrosion by electrolyte and effectively suppressed electron recombination. The UV-vis spectra revealed an enhanced absorption especially in the long wavelength range after modification. The XRD results showed a disappeared peak of PbI₂, demonstrating that the modification could effectively protect the perovskite from dissolution in the electrolyte. Stability test showed that the remaining J_SC improved from 10% to 50% at a given period of time. The EIS results and dark current curves illustrated that this modification increased the interface resistance in dark, confirming that the electron recombination process was effectively restrained. Finally, the corresponding efficiency was largely increased from 3.56 to 6.00% by 68%. The strategy using aluminium oxide to post-modify a perovskite sensitized solar cell was therefore proved to be a useful tool for the optimization of perovskite sensitized solar cells.