Recently, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has been developed to exceed 25%, and charge transport layer optimization is a promising strategy for further efficiency improvement in PSCs. Herein, a supramolecular complex [(CH)N][SiWO] (TASiW-12) is synthesized and its doped form in SnO (hereafter S-SnO) is used as a charge transport layer (electron transport layer, ETL). This study demonstrates that S-SnO introduction is a practical and effective way to improve the bulk ETL and those of the ETL/perovskite interface. S-SnO leads to improved band alignment, suppressed trap-assisted charge recombination, and enhanced electron mobility. In addition, an enhanced open-circuit voltage (V) of 1.16 V and an efficiency of 22.8% are successfully achieved in n–i–p planar PSCs. Meanwhile, S-SnO acts as a crucial agent to reduce charge accumulation at the S-SnO/perovskite interface. The device possesses superior stability for 3072 h with only a 5.65% loss of the initial PCE. These results indicate that high-efficiency PSCs can be easily attained by introducing a TASiW-12-doped ETL with integrated functions.