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One of the most important factors governing the photovoltaic efficiency and environmental stability of Perovskite Solar Cells (PSCs) is the quality of their perovskite films. However, the present study demonstrates that CH3NH3PbI3perovskite films after anti-solvent washing are far from perfect on the surface, where the crystallization degree is quite low with complex multi-phases associated with numerous defects and notable chemical inhomogeneity. Herein, we report a novel anti-solvent washing treatment simply using Hydrogen Iodide (HI) additive in chlorobenzene (CB) which can enormously improve CH3NH3PbI3films surface with high crystallization phase purity and chemical homogeneity, leading to excellent structural stability under humidity, heat and even tensile force. Based on such high quality films with defect-less surface, fabricated planar PSCs with an architecture of ITO/TiO2/CH3NH3PbI3/Spiro-OMeTAD/MoOx/Au present a champion PCE of 19.94% and improved stability under humidity. Moreover, fabricated flexible planar PSCs on PET/ITO substrates with a champion PCE of 17.32% are shown to be more robust under tensile force than their control devices. The present study thus not only provides more insight into the facile defects passivation process on the surface achieved viabalancing halide ions, but also provides a practical but efficient treatment which can be widely used to fabricate high quality CH3NH3PbI3films for environmentally stable high performance device applications.

All-inorganic quantum dot (QD) light-emitting diodes (AI-QLEDs) with excellent stability received enormous interest in the past few years. Nevertheless, the vast energy offset and the high trap density at the NiOX/QDs interface limit hole injection leading to fluorescence quenching and hampering the performance. Here, we present self-assembled monolayers (SAMs) with phosphonic acid (PA) anchoring groups modifying NiOXhole transport layer (HTL) to tune energy level and passivate trap states. This strategy facilitates hole injection owning to the well-aligned energy level by interface dipole, downshifting the vacuum level, reducing the hole injection barrier from 0.94eV to 0.28eV. Meanwhile, it mitigates the interfacial recombination by passivating surface hydroxyl group (-OH) and oxygen vacancy (VO) traps in NiOX. The electron leakage from QDs toward NiOXHTL is significantly suppressed. The all-inorganic R-QLEDs exhibit one of the highest maximum luminance, external quantum efficiency and operational lifetime of 88980cdm−2, 10.3% and 335045h (T50@100cdm−2), respectively. The as-proposed interface engineering provides an effective design principle for high-performance AI-QLEDs for future outdoor and optical projection-type display applications.

The phase control and ordered crystal growth play a crucial role in the efficiency and stability of all-inorganic perovskite solar cells (PSCs). However, the innate dynamics of crystal growth driving the stable phase and high performance are unknown. Here, we for the first time unraveled that the degree of lattice strain is responsible for the suppression of the δ phase growth by in situ Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) technique. We shadow the internal crystal structural changes in real time and successfully decoupled crystal growth dynamics under different substrate temperatures. The symmetrical crystal lattice and vertical substrate growth were finally achieved. This finding provides insights on the inorganic perovskite crystal growth and has significant benefit for high performing all-inorganic PSCs.