A lateral photodetector based on the bilayer composite film of a perovskite and a conjugated polymer is reported. It exhibits significantly enhanced responsivity in the UV-vis region and sensitive photoresponse in the near-IR (NIR) region at a low applied voltage. This broadband photodetector also shows excellent mechanical flexibility and improved environmental stability.

Halide perovskites have high light absorption coefficients, long charge carrier diffusion lengths, intense photoluminescence, and slow rates of non-radiative charge recombination. Thus, they are attractive photoactive materials for developing high-performance optoelectronic devices. These devices are also cheap and easy to be fabricated. To realize the optimal performances of halide perovskite-based optoelectronic devices (HPODs), perovskite photoactive layers should work effectively with other functional materials such as electrodes, interfacial layers and encapsulating films. Conventional two-dimensional (2D) materials are promising candidates for this purpose because of their unique structures and/or interesting optoelectronic properties. Here, we comprehensively summarize the recent advancements in the applications of conventional 2D materials for halide perovskite-based photodetectors, solar cells and light-emitting diodes. The examples of these 2D materials are graphene and its derivatives, mono- and few-layer transition metal dichalcogenides (TMDs), graphdiyne and metal nanosheets, etc. The research related to 2D nanostructured perovskites and 2D Ruddlesden-Popper perovskites as efficient and stable photoactive layers is also outlined. The syntheses, functions and working mechanisms of relevant 2D materials are introduced, and the challenges to achieving practical applications of HPODs using 2D materials are also discussed.

A flexible air electrode (FAE) with both high oxygen electrocatalytic activity and excellent flexibility is the key to the performance of various flexible devices, such as Zn-air batteries. A facile two-step method, mild acid oxidation followed by air calcination that directly activates commercial carbon cloth (CC) to generate uniform nanoporous and super hydrophilic surface structures with optimized oxygen-rich functional groups and an enhanced surface area, is presented here. Impressively, this two-step activated CC (CC-AC) exhibits superior oxygen electrocatalytic activity and durability, outperforming the oxygen-doped carbon materials reported to date. Especially, CC-AC delivers an oxygen evolution reaction (OER) overpotential of 360 mV at 10 mA cm −2 in 1 m KOH, which is among the best performances of metal-free OER electrocatalysts. The practical application of CC-AC is presented via its use as an FAE in a flexible rechargeable Zn-air battery. The bendable battery achieves a high open circuit voltage of 1.37 V, a remarkable peak power density of 52.3 mW cm −3 at 77.5 mA cm −3 , good cycling performance with a small chargedischarge voltage gap of 0.98 V and high flexibility. This study provides a new approach to the design and construction of high-performance selfsupported metal-free electrodes.

We presented a new type II heterojunction photocatalyst with a strong built-in electric field aligned between the spatially well-defined redox sites to effectively suppress the charge recombination for efficient photocatalytic hydrogen generation via HI splitting. This brings the hydrogen generation performance of the perovskite-based photocatalysts to a new horizon with a champion STH efficiency of 1.09% and a record hydrogen generation activity of 13.6 mmol g À1 h À1 under visible light.

A series of mono- and bisadducts of thieno-o-quinodimethane with C(60) (TOQC) was efficiently prepared through the Diels-Alder reaction of pristine or solubilizing side-chain-substituted 2,3-bis(chloromethyl)thiophene with C(60). The pristine TOQC bisadduct (bis-TOQC) shows much higher performance than the side-chain-substituted TOQC bisadducts in polymer solar cells, while the situation is inverse for the TOQC monoadducts. The best power conversion efficiency of 5.1% was achieved from the bis-TOQC:P3HT solar cells under simulated AM1.5G irradiation (86 mW/cm(2)).

Solar‐energy‐powered photocatalytic fuel production and chemical synthesis are widely recognized as viable technological solutions for a sustainable energy future. However, the requirement of high‐performance photocatalysts is a major bottleneck. Halide perovskites, a category of diversified semiconductor materials with suitable energy‐band‐enabled high‐light‐utilization efficiencies, exceptionally long charge‐carrier‐diffusion‐length‐facilitated charge transport, and readily tailorable compositional, structural, and morphological properties, have emerged as a new class of photocatalysts for efficient hydrogen evolution, CO2 reduction, and various organic synthesis reactions. Despite the noticeable progress, the development of high‐performance halide perovskite photocatalysts (HPPs) is still hindered by several key challenges: the strong ionic nature and high hydrolysis tendency induce instability and an unsatisfactory activity due to the need for a coactive component to realize redox processes. Herein, the recently developed advanced strategies to enhance the stability and photocatalytic activity of HPPs are comprehensively reviewed. The widely applicable stability enhancement strategies are first articulated, and the activity improvement strategies for fuel production and chemical synthesis are then explored. Finally, the challenges and future perspectives associated with the application of HPPs in efficient production of fuels and value‐added chemicals are presented, indicating the irreplaceable role of the HPPs in the field of photocatalysis.

Bismuth‐based perovskites are promising candidates for lead‐free and air‐stable photovoltaics. However, the poor surface morphologies and high exciton binding energy of the bismuth‐based perovskites have limited their performances. Herein, the density functional theory calculations unveil that CsBi3I10 possesses favorable optoelectronic properties such as a narrow bandgap, a small effective mass, and relatively high electron mobility. To tackle the poor‐surface morphology problem, the high‐quality CsBi3I10 films are fabricated via gas‐assisted spin‐coating and solvent vapor annealing in ambient conditions. Using the [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) as the electron acceptor, an optimized inverted CsBi3I10/PCBM bulk‐heterojunction structure enables a high power conversion efficiency of 1.18% among the CsBi3I10‐based perovskite solar cells. The approach exemplified in this work could be useful for designing the high‐performance Bi‐based lead‐free perovskite solar cells.

A non-noble-metal bifunctional catalyst with efficient and durable activity towards both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) is crucial to the development of rechargeable Zn-air batteries. Herein, a facile one-step hydrothermal method is reported for the synthesis of a high-performance bifunctional oxygen electrocatalyst, cobalt-doped Mn 3 O 4 nanocrystals supported on graphene nanosheets (Co-Mn 3 O 4 /G). Compare to pristine Mn 3 O 4 , this Co-Mn 3 O 4 /G exhibits greatly enhanced electrocatalytic activity, delivering a halfwave potential of 0.866 V for the ORR and a low overpotential of 275 mV at 10 mA cm À2 for the OER. The zinc-air battery built with Co-Mn 3 O 4 /G shows a reduced charge-discharge voltage of 0.91 V at 10 mA cm À2 , an power density of 115.24 mW cm À2 and excellent stability without any degradation after 945 cycles (315 h), outperforming the state-of-the-art Pt/C-Ir/C catalyst-based device.