Defect passivation via post-treatment of perovskite films is an effective method to fabricate high-performance perovskite solar cells (PSCs). However, the passivation durability is still an issue due to the weak and vulnerable bonding between passivating functional groups and perovskite defect sites. Here we propose a cholesterol derivative selfassembly strategy to construct crosslinked and compact membranes throughout perovskite films. These supramolecular membranes act as a robust protection layer against harsh operational conditions while providing effective passivation of defects from surface toward inner grain boundaries. The resultant PSCs exhibit a power conversion efficiency of 23.34 % with an impressive open-circuit voltage of 1.164 eV. The unencapsulated devices retain 92 % of their initial efficiencies after 1600 h of storage under ambient conditions, and remain almost unchanged after heating at 85 °C for 500 h in a nitrogen atmosphere, showing significantly improved stability.

The interface of perovskite solar cells (PSCs) is significantly important for charge transfer and device stability, while the buried interface with the impact on perovskite film growth has been paid less attention. Herein, we use a molecular modifier, glycocyamine (GDA) to build a molecular bridge on the buried interface of SnO2/perovskite, resulting in superior interfacial contact. This is achieved through the strongly interaction between GDA and SnO2, which also appreciably modulates the energy level. Moreover, GDA can regulate the perovskite crystal growth, yielding perovskite film with enlarged grain size and absence of pinholes, exhibiting substantially reduced defect density. Consequently, PSCs with GDA modification demonstrate significant improvement of open circuit voltage (close to 1.2 V) and fill factor, leading to an improved power conversion efficiency from 22.60 % to 24.70 %. Additionally, stabilities of GDA devices under maximum power point and 85 °C heat both perform better than the control devices.

Metal oxides are the most efficient electron transport layers (ETLs) in perovskite solar cells (PSCs). However, issues related to the bulk (i.e., insufficient electron mobility, unfavorable energy level position) and interface of metal oxide/perovskite (detrimental surface hydroxyl groups) limit the transport kinetics of photoinduced electrons and prevent PSCs from unleashing their theoretical efficiency potential. Herein, the inorganic InP colloid quantum dots (CQDs) with outstanding electron mobility (4600 cm2 V–1 s–1) and carboxyl (−COOH) terminal ligands were uniformly distributed into the metal oxide ETL to form consecutive electron transport channels. The hybrid InP CQD-based ETL demonstrates a more N-type characteristic with more than 3-fold improvement in electron mobility. The formation of the Sn–O–In bond facilitates electron extraction due to suitable energy level alignment between the ETL and perovskite. The strong interaction between uncoordinated Pb2+ at the perovskite/ETL interface and the −COO– in the ligand of InP CQDs reduces the density of defects in perovskite. As a result, the hybrid InP CQD-based ETL with an optimized InP ratio (18 wt %) boosts the power conversion efficiency of PSCs from 22.38 to 24.09% (certified efficiency of 23.43%). Meanwhile, the device demonstrates significantly improved photostability and atmospheric storage stability.

The interfaces between the absorber and charge transport layers are shown to be critical for the performance of perovskite solar cells (PSCs). PSCs based on the Spiro-OMeTAD hole transport layers generally suffer from the problems of stability and reproducibility. Inorganic hole transport materials CuCrO 2 have good chemical stability and high hole mobility. Herein, we reported the preparation of the delafossite-type CuCrO 2 nanocrystals with a template-etching-calcination method and the incorporation of the as-obtained CuCrO 2 nanocrystals at the perovskite/ Spiro-OMeTAD interfaces of planar PSCs to improve the device efficiency and stability. Compared with the traditional hydrothermal method, the template-etchingcalcination method used less calcination time to prepare CuCrO 2 nanocrystals. After the CuCrO 2 interface modification, the efficiency of PSCs improved from 18.08% to 20.66%. Additionally, the CuCrO 2 -modified PSCs showed good stability by retaining nearly 90% of the initial PCE after being stored in a drybox for 30 days. The template-etching-calcination strategy will pave a new approach for the synthesis of high-performance inorganic hole-transporting materials.

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A high-conductivity thiocyanate ionic liquid (EMIMSCN) was introduced into perovskite solar cells for the first time. The high conductivity of EMIMSCN ensures adequate supply of free SCN- anions and EMIM+...

Defect passivation via post‐treatment of perovskite films is an effective method to fabricate high‐performance perovskite solar cells (PSCs). However, the passivation durability is still an issue due to the weak and vulnerable bonding between passivating functional groups and perovskite defect sites. Here we propose a cholesterol derivative self‐assembly strategy to construct crosslinked and compact membranes throughout perovskite films. These supramolecular membranes act as a robust protection layer against harsh operational conditions while providing effective passivation of defects from surface toward inner grain boundaries. The resultant PSCs exhibit a power conversion efficiency of 23.34 % with an impressive open‐circuit voltage of 1.164 eV. The unencapsulated devices retain 92 % of their initial efficiencies after 1600 h of storage under ambient conditions, and remain almost unchanged after heating at 85 °C for 500 h in a nitrogen atmosphere, showing significantly improved stability.

Wide‐bandgap perovskite solar cells (PSCs) are attracting increasing attention because they play an irreplaceable role in tandem solar cells. Nevertheless, wide‐bandgap PSCs suffer large open‐circuit voltage (VOC) loss and instability due to photoinduced halide segregation, significantly limiting their application. Herein, a bile salt (sodium glycochenodeoxycholate, GCDC, a natural product), is used to construct an ultrathin self‐assembled ionic insulating layer firmly coating the perovskite film, which suppresses halide phase separation, reduces VOC loss, and improves device stability. As a result, 1.68 eV wide‐bandgap devices with an inverted structure deliver a VOC of 1.20 V with an efficiency of 20.38%. The unencapsulated GCDC‐treated devices are considerably more stable than the control devices, retaining 92% of their initial efficiency after 1392 h storage under ambient conditions and retaining 93% after heating at 65 °C for 1128 h in an N2 atmosphere. This strategy of mitigating ion migration via anchoring a nonconductive layer provides a simple approach to achieving efficient and stable wide‐bandgap PSCs.