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Effectively encapsulating perovskite solar cells (PSCs) to enhance the external reliability is the key towards commercialization. We herein propose a facile encapsulation method by introducing conductive ribbons and a polyethylene terephthalate (PET) backsheet on both sides of PSC. Via applying thermoplastic polyolefin (TPO) encapsulant, we implemented PSCs with fine encapsulation, enabling considerable durability in the ambient atmosphere and even with water immersion, demonstrating almost no degradation in the device output, which is ascribed to the low water vapor transmission rate as well as the high chemical stability of TPO. The operation reliability of the encapsulated cell is also significantly increased, maintaining 80% of the initial efficiency after 770 hours' light illumination in an ambient atmosphere. This novel encapsulation route provides a feasible idea for the commercial application of PSCs in the future. [ABSTRACT FROM AUTHOR]

Reducing the interfacial defects between the perovskite/electron transport layer (ETL) is the key point to improving the efficient and stable performance of perovskite solar cells (PSCs). In this study, two self-assembled molecules ((aminomethyl)phosphonic acid and glycine) with different functional groups (phosphonic acid (-H2PO3) and carboxylic acid (-COOH)) were mixed to form the buried bottom interface of PSCs. The synergistic effect of -H2PO3 with its higher anchoring ability and -COOH with its fast carrier transport improved the performance of PSCs. Additionally, the SnO2 modified by mixed self-assembly molecules (M-SAM) showed a more appropriate energy level alignment, favoring charge transport and minimizing energy loss. In addition, the amine group (-NH2) on the two small molecules effectively interacted with uncoordinated Pb2+ in perovskite and improved the quality of the perovskite films. Consequently, the (FAPbI3)0.992(MAPbBr3)0.008 PSCs with M-SAM reached a PCE of 24.69% (0.08 cm2) and the perovskite modules achieved a champion efficiency of 18.57% (12.25 cm2 aperture area). Meanwhile, it still maintained more than 91% of its initial PCE after being placed in nitrogen atmosphere at 25 °C for 1500 h, which is better than that of the single-SAM and control devices. Further reference is provided for the future commercialization of perovskite with efficient and stable characteristics. [ABSTRACT FROM AUTHOR]

Titanium oxide (TiO 2) and tin oxide (SnO 2) are the most commonly used electron transport materials for high-efficiency n-i-p perovskite solar cells (PSCs); however, several limiting properties of TiO 2 and SnO 2 adversely affect device performance. This study describes a facile method to synthesize SnO 2 :TiO 2 hybrid nanocrystals (NCs) to construct electron transport layers (ETLs) with the advantageous properties of both SnO 2 and TiO 2 for n-i-p PSCs. The optimized SnO 2 :TiO 2 ETL exhibited better surface morphology, well-matched band alignment, higher direct current conductivity, and enhanced electron extraction and transport compared to pristine TiO 2 and SnO 2 ETLs. Moreover, perovskite films deposited on SnO 2 :TiO 2 ETLs exhibited a higher crystallinity and lower trap-state density than those on TiO 2 or SnO 2 ETLs. Therefore, SnO 2 :TiO 2 -based devices showed high performance (with a power conversion efficiency of 23.19%) and stability (with more than 83% retention of the initial efficiency after 800 h of continuous illumination). This study provides a new method for developing low-cost and efficient ETLs for n-i-p PSCs and confirms that constructing SnO 2 :TiO 2 hybrid ETL is an effective method to fabricate high-efficiency and stable planar perovskite solar cells. [Display omitted] • A facile method was developed to synthesize SnO 2 :TiO 2 hybrid nanocrystals. • The SnO 2 :TiO 2 hybrid ETL exhibited the advantageous properties of both TiO 2 and SnO 2. • Perovskite films deposited on SnO 2 :TiO 2 ETLs exhibited a high crystallinity and low trap-state density. • SnO 2 :TiO 2 -based devices had a PCE of 23.19% with >83% retention after 800 h of continuous illumination. [ABSTRACT FROM AUTHOR]

As the power conversion efficiency (PCE) of perovskite solar cells (PSCs) is increased to as high over 25%, it becomes pre‐eminent to study a scalable process with wide processing window to fabricate large‐area uniform perovskite films with good light‐trapping performance. A stable and uniform intermediate‐state complex film is obtained by using tetramethylene sulfoxide (TMSO), which extends the annealing window to as long as 20 min, promotes the formation of a high‐quality perovskite film with larger grains (over 400 nm) and spontaneously forms the surface texture to result in an improved fill factor and open‐circuit voltage (Voc). Moreover, the superior surface texture significantly increases the long‐wavelength response, leading to an improved short‐circuit current density (Jsc). As a result, the maximum PCE of 21.14% is achieved based on a simple planar cell structure without any interface passivation. Moreover, a large area module with active area of 6.75 cm2 is assembled using the optimized TMSO process, showing efficiency as high as 16.57%. The study paves the way to the rational design of highly efficient PSCs for potential scaled‐up production. [ABSTRACT FROM AUTHOR]