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In inverted perovskite solar cells (PSCs), n‐doping fullerene electron transport layers (ETLs) have been found to prepare high efficiency devices due to their excellent performance in electrochemistry, film formability, and surface passivation. Herein, two cathode interface layers (CILs) 2PDI‐FN and 2PDIT‐FN are prepared with dimethylamino functional groups and PDI units. The addition of thiophene makes the 2PDIT‐FN conjugated framework coplanar and enhances the effect of dimethylamino functional groups, which give 2PDIT‐FN with higher electrical conductivity, electron mobility, self‐doping property, and film formability. Moreover, dopant N‐DMBI can further enhance these advantages of 2PDIT‐FN. Consequently, a peak power conversion efficiency (PCE) of 20.44% is achieved with 2PDIT‐FN(+) as CIL, much higher than 18.77% of 2PDI‐FN(+) one, which is only 17.71% and 19.06% for 2PDI‐FN and 2PDIT‐FN‐based one, respectively. The significant improvement in device efficiency is due to reduced defect density, lower dark current, larger recombination resistance, and better surface morphology, which improves charge transport and collection at the PC61BM/Ag interface. In a word, this molecular design approach with molecular configuration regulation and functional groups provides a direction for the preparation of cathode interface materials to achieve high performance of PSCs. [ABSTRACT FROM AUTHOR]

All-inorganic metal halide perovskite is considered as one of the most promising perovskite materials for photodetectors, because of its remarkable optoelectronic characteristics and stability. Whereas, it remains challenge to achieve both excellent photodetection performance and stability due to the multitudes of defects in perovskite films. Herein, an interface engineering based on surface passivation strategy to achieve high-quality CsPbBr 3 perovskite films by introducing thioacetamide (C 2 H 5 NS, abbreviated as TAA) as interface materials is reported. The interaction between TAA and perovskite passivates the uncoordinated Pb2+ on the surface of CsPbBr 3 film, suppress carrier non-recombination and accelerates carriers transfer. The self-powered photodetector based on the passivated CsPbBr 3 film prefers the maximum responsivity of 0.26 A W−1 and detectivity of 8.39 × 1012 Jones under 520 nm irradiation. In addition, the optimized photodetector exhibits excellent stability and maintains more than 98% of its initial photocurrent when operating over 8 h. This work demonstrates an alternative approach for the preparation of improved performance in CsPbBr 3 perovskite photodetectors and associated photoelectric devices. [Display omitted] • Introducing thioacetamide into the perovskite device as interface layer. • The device is self-powered, high-detectivity and rapidly detection to radiation. • The device achieved a champion responsivity of 0.26 A/W with excellent stability. [ABSTRACT FROM AUTHOR]

Perylene diimide-based small molecular (PDI-4N) was designed and synthesized through a smiple one-step reaction as efficient cathode interface layers (CIL) in inverted PVSC, and PDI-2N was also synthesized as a contrast. Multi-dimethyl amine groups in the N- and bay- positions of PDI-4N give PDI4N better alcohol solubility, higher conductivity, electron mobility, self-doping property. Corresponding inverted PVSC with PDI-4N CIL manifests a promising power conversion efficiency (PCE) of 21.33%, and synthetic complexity (SC) and industrial figure of merit (IFOM) of PDI-4N are very low than many other cathode interface materials having been reported. Moreover, good stability with a PCE loss of only ∼2.0 % after 600 h is also obtained for PDI-4N based device. [Display omitted] • Two PDI-based cathode interfacial materials were synthesized with a simple method. • The promising synthetic complexity (SC) of 13.95 % and IFOM of 0.65 are obtained. • PCEs of up to 21.33 % in perovskite solar cells were obtained with good stability. Interface engineering plays an important role in improving the performance of perovskite devices. Herein, we reported two perylenediimide small molecular cathode interface materials (CIMs), PDI-2N and PDI-4N, synthesized by a simple method and with good alcohol soluble, which could be used as cathode interfacial layer (CIL) for high-performance inverted perovskite solar cells (PVSCs). The PDI-4N exhibits larger electrical conductivity, electron mobility and self-doping properties than PDI-2N because of more dimethylamino functional groups in the amide positions. Based on these superiorities, a peak PCE of 21.33% with PDI-4N as CIL was achieved, which is the highest PCE for PDI-based interlayer materials as the cathode interlayer in inverted PVSCs. While the PCE with PDI-2N as CIL is only 17.41%. The significant improvement in device efficiency for PDI-4N based device is due to reduced defect density, lower dark current, larger recombination resistance and better surface morphology, which improved charge transport and collection at the PC 61 BM/Ag interface. Moreover, the ambient stabilities of PVSCs with PDI-2N and PDI-4N as CIL show that the CILs can effectively improve the device stability, and good stability with a PCE loss of only ∼3.0% after 600 h is also obtained. In a word, this work will provide us with molecular design approach by one-step to develop novel cathode interface materials with functional side chains for high-efficiency PVSCs. [ABSTRACT FROM AUTHOR]

• MAPbCl 3 and amorphous Ga 2 O 3 formed a hybrid structure for the first time. • The responsivity enhanced nearly 70 times by inserting the amorphous Ga 2 O 3 layer. • The MAPbCl 3 /amorphous Ga 2 O 3 photodetector is sensitive with high-detectivity. • The performance of polycrystalline detector is comparable to single crystal device. • The detector is self-powered and realizes accurate detection of UVA radiation. [Display omitted] UVA radiation can survive from the absorption of atmospheric layer and reaches the terrestrial surface, which is harmful to human eyes, blood vessels, and elastic fibers. It is meaningful to detect the UVA radiation precisely. A sensitive, high-detectivity and self-powered UVA detector based on polycrystalline CH 3 NH 3 PbCl 3 /amorphous Ga 2 O 3 hybrid structure is presented in this work. Under zero bias, the rise/decay time of the photodetector are 56/67 ms, and the detectivity reaches up to 5.4 × 1010 Jones. The performance is even superior to most of the reported devices based on CH 3 NH 3 PbCl 3 single crystal. The heterojunction between amorphous Ga 2 O 3 and CH 3 NH 3 PbCl 3 accelerates the separation of photon-generated carrier and effectively reduces the recombination. In addition, the high resistivity and low surface roughness of the amorphous Ga 2 O 3 layer also contribute to the improvement of device parameters. This study offers new insights to improve the polycrystalline MAPbCl 3 devices by ultra-wide bandgap amorphous semiconductors. [ABSTRACT FROM AUTHOR]