摘要： Carbon dots (CDs) have significant potential in the chemical decoration, crystal modification, and surface passivation of perovskite photovoltaics. However, incompatibility between the hydrophilic/hygroscopic nature of CDs and moisture sensitive perovskite remains an issue. Solving this problem would yield a significant improvement for stable perovskite devices embedded with CDs. Herein, the hydrophobic passivation layers are realized for perovskite solar cells (PSCs) through the surface engineering of CDs, exploiting electrostatic self–assembly of trichloro(3,3,3–trifluoropropyl)silane (C3H4Cl3F3Si) and CDs. The embedded CDs modify perovskite grains and passivate grain boundary defects, thereby promoting the carrier lifetime and charge collection. The inserted C3H4Cl3F3Si insulating layer provides the tunneling junction at the contact of perovskite and electron transport layer. This tunneling layer can selectively conduct electrons and block the holes, which spatially separate photo–generated carriers to suppress their recombination. As a result, the optimized perovskite devices deliver the highest efficiency of 21.12% with a high fill factor of 82.86%. Moreover, the variation of surface wettability can be achieved by the self–assembly of C3H4Cl3F3Si, which improves the stability of perovskite devices by maintaining nearly 90% efficiency forover 30 days’ exposure to ambient without encapsulation.