HighlightsThe 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.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40820-023-01145-y.