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)).