ASSOCIATED CONTENT

Supporting Information

Figure S1. (a) UV–Vis spectra of the annealed perovskite films on ZnO before and after air

exposure and (b) XRD patterns of the corresponding perovskite films.

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Figure S2. Photographs of the annealed perovskite films on ZnO at different post-treatment

temperatures.

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Table S1. Fitting parameters for EIS measurements performed under white LED illumination.

Figure S3. (a) Transport resistance and (b) charge transfer resistance of TiCl4-treated ZnO based perovskite solar cell at different applied biases.

Figure S4. (a) Images of large-area devices and (b) J-V curves of the best performing device; (c) Statistical results of the large-area devices.

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