Organic-inorganic hybrid perovskite semiconductors pos-sessing superior optoelectronic properties (e.g.long carrier dif-fusion lengths,high optical absorption coefficient,low ex-citon binding energy,and high defect tolerance) are attract-ing serious attention.The certified power conversion effi-ciency (PCE) for single-junction perovskite solar cells have ex-ceeded 25％[1,2].As a very promising PCE-enhancement strategy,tandem structure made by stacking a perovskite cell on a market-dominant silicon cell can yield much higher PCEs beyond the Shockley-Queisser limit of single-junction devices without adding substantial cost[3].To satisfy current-match-ing in tandem configuration,the top perovskite cell requires an ideal bandgap of ～1.7 eV rather than the ones (～1.5-1.6 eV)typically used for highly efficient single-junction perovskite devices given that the bottom silicon cell holds a bandgap of 1.12 eV[4].Such wide-bandgap perovskites achieved through I/Br alloying usually suffer from photoinduced phase segrega-tion and relatively low radiative efficiency,which inevitably result in large open-circuit voltage (Voc) deficits[5,6].Several strategies like adjusting perovskite composition[7,8],additive engineering[9,10],and upper surface passivation[11,12] have been utilized to stabilize these wide-bandgap perovskites and improve film quality to reduce Voc losses.The reported pe-rovskite/silicon tandem devices suffer from low Voc (＜1.9 V)and PCEs (≤28％)[13].There is still a large room for enhancing PCEs given that the predicted PCE limit is beyond 30％ for this tandem technology[14].