Gelation of Hole Transport Layer to Improve the Stability of Perovskite Solar Cells

Highlights The gelation of hole transport layer generates a dense and uniform hole transport layer film and significantly inhibits the aggregation of lithium bis(trifluoromethane sulfonyl)imide in spiro-OMeTAD. The gelated hole transport layer confers enhanced charge carrier transport and better humidity and operational stability of perovskite solar cells.