Surface passivation is increasingly one of the most prominent strategies to promote the efficiency and stability of perovskite solar cells (PSCs). However, most passivation molecules hinder carrier extraction due to poorly conductive aggregation between perovskite surface and carrier transportation layer. Herein, a novel molecule: p-phenyl dimethylammonium iodide (PDMAI) with ammonium group on both terminals is introduced, and its passivation effect is systematically investigated. It is found that PDMAI can mitigate defects at the surface and promote carrier extraction from perovskite to the hole transporting layer, leading to a lift of open-circuit voltage of 40 mV. Profiting from superior PDMAI passivation, the average efficiency of PSCs has been elevated from 19.69% to 20.99%. As demonstrated with density functional theory calculations, PDMAI probably tends to anchor onto the perovskite surface with both NH 3 I tails, and enhances the adhesion and contact to perovskite layer. The exposed hydrophobic aryl core protects perovskite against detrimental environmental factors. In addition, the alkyl component between aryl and ammonium groups is demonstrated to be essentially vital in triggering passivation function, which offers the guidance for the design of passivation molecules.

Owing to large steric hindrance, white light hyperbranched conjugated polymers exhibited the best electroluminescent performance with suppression of triplet–triplet annihilation.

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Although perovskite solar cells (PSCs) with organic hole-transporting layers (HTLs) have demonstrated the certified power conversion efficiency (PCE) over 25%. Unavoidable performance degradation in the atmosphere is still one of the key hurdles facing the practical application. In this work, low-temperature solution-processed CuSCN was attempted as the inorganic HTL, which has been expected to provide an appreciable enhancement in device stability. In addition, concerning the potential-induced degradation around the CuSCN/Au interface, a thin PTB7 layer was inserted as a spacer, yielding a dramatically promoted device stability. Furthermore, in order to avoid the destruction to perovskites by the solvent of CuSCN, PTAA was attempted as a protection sheath of perovskites. Consequently, with optimized dual-interface engineering, the best performing cell delivers a PCE of 18.41% (average 17.63%) and maintains approximately 98.8% of the initial value more than 1000 h without encapsulation, manifesting the superior stability. This approach paves a way for achieving PSCs with both high efficiency and long-term durability.