Synergetic effects of electrochemical oxidation of Spiro-OMeTAD and Li+ ion migration for improving the performance of n–i–p type perovskite solar cells

Oxidation of solar cells leads to Li⁺ ion diffusion, which increases the conductivity of the Spiro-OMeTAD layer and the built-in potential within the cells. The synergetic effects improve charge injection at both interfaces and device performance.