All-inorganic perovskite solar cells suffer from low performance due to unsatisfactory carrier transport and light harvesting efficiency. Semiconductor nanopillar arrays can reduce light reflection loss and suppress exciton recombination dynamics in optoelectronic devices. In all-inorganic perovskite solar cells, few studies employing TiO₂ nanopillar arrays (TiO₂ NaPAs) have been reported to improve the device performance. Herein, well-arranged TiO₂ NaPAs are chosen to enhance the interfacial contact between perovskite and electron transporting layers for improving the carrier transport. Notably, TiO₂ NaPAs can be directly fabricated on rigid/flexible substrates at roughly room temperature by unique glancing angle deposition, which is more available than high-temperature hydrothermal/solvothermal methods. By embedding TiO₂ NaPAs into chemical processable CsPbI₂Br layers, continuous and intimate films are readily formed, guaranteeing large physical contact for facilitating more effective electron injection and charge separation. The vertically grown TiO₂ NaPAs also provide a straightforward electron transporting path to electrodes. In addition, TiO₂ NaPAs can guide the incident light and enhance the light-harvesting ability of CsPbI₂Br films. As a result, the solar cell with TiO₂ NaPAs displays a power conversion efficiency of 11.35% higher than planar control of 10.04%, and exhibits better long-term thermal stability. This strategy provides an opportunity by constructing direct interfacial regulation towards the performance improvement of inorganic perovskite solar cells.

Two-dimensional materials have been demonstrated as promising toolboxes for optoelectronics. Transition metal carbides and nitrides (MXenes), members of an emerging family of two-dimensional materials, have drawn extensive attention in optoelectronics owing to their excellent conductivity and tunable electronic properties. Herein, a photodetector based on the two-dimensional van der Waals heterostructure of Ti₃C₂T_x MXene and a MoS₂ monolayer was constructed to observe the ambipolar photoresponse, which showed a positive photoresponse in the visible spectrum (500–700 nm) and a negative photoresponse at longer wavelengths (700–800 nm). The device exhibited a high negative responsivity of 1.9 A/W and a detectivity of 2.1 × 10¹⁰ Jones under 750 nm light illumination. Detailed experiments demonstrate that the negative photoresponse arises from the heterostructure- induced trap energy level, which confines the excited photoelectrons and leads to an inverse current. This work demonstrates a unique optoelectronic phenomenon in MoS₂/MXene heterostructures and provides valuable insights into the development of new photodetection materials.

The inert basal plane of molybdenum disulfide (MoS₂) restrains its further hydrogen evolution reaction (HER) performance. This work attempts ion irradiation to activate inert basal plane of MoS₂ nanosheet to improve its electrocatalytic performance. Experimental results demonstrate the sulphur vacancies generated by ion irradiation on the basal plane of MoS₂ mainly boost the efficiency of HER performance. The moderate fluence of carbon ion irradiation gains the optimum HER performance with an onset potential of 77 mV and Tafel slope of 66 mV/dec.

High-performance electrocatalysts for water splitting at all pH values have attracted considerable interest in the field of sustainable hydrogen evolution. Herein, we report an efficient electrocatalyst with a nanocrystalline cobalt phosphide (CoP) network for water splitting in the pH range of 0-14. The novel flexible electrocatalyst is derived from a desirable nanocrystalline CoP network grown on a conductive Hastelloy belt. This kind of self-supported CoP network is directly used as an electrocatalytic cathode for hydrogen evolution. The nanocrystalline network structure results in superior performance with a low onset overpotential of ~45 mV over a broad pH range of 0 to 14 and affords a catalytic current density of 100 mA·cm^-2 even in neutral media. The CoP network exhibits excellent catalytic properties not only at extreme pH values (0 and 14) but also in neutral media (pH = 7), which is comparable to the behavior of state-of-the-art platinum-based metals. The system exhibits an excellent flexible property and maintains remarkable catalytic stability during continuous 100-h-long electrolysis even after 100 cycles of bending/extending from 100° to 250°.