摘要： The collocation between charge transport layer and photoactive layer is extremely critical in solar energy conversion devices. More recently, it is especially prominent for promising planar perovskite solar cell based on SnO2 electron transfer layer (ETL) due to its unmatched photogenerated electron and hole extraction rates. Thereby, graphdiyne (GDY) with multi-roles has been incorporated to maximize the collocation between SnO2 and perovskite regarding perspectives of electron extraction rate optimization as well as the interface engineering for perovskite growth inducement and interfacial defect passivation, enabling such interfacial function towards both perovskite crystallization process and subsequent photovoltaic service duration. The GDY doped SnO2 layer finally results 4-times improved electron mobility and more facilitated band alignment. Simultaneously, the enhanced hydrophobicity effectively inhibits heterogeneous perovskite nucleation, contributing to high quality film with diminished grain boundaries and lower defect density. The systematical density functional theory study has further indicated that freshly formed C-O σ bond resulted electrical property enhancement and the passivated Pb-I antisite defects are both originated from GDY introduction. The 21.11% power conversion efficiency with negligible hysteresis indicate such scenario may trigger unlimited reverie of promising GDY materials and provide more insights on elaborately interfacial design in perovskite solar cells.