Metal halide perovskite solar cells (PSCs) are one of the most promising photovoltaic devices. Over time, many strategies have been adopted to improve PSC efficiency, and the certified efficiency has reached 26.1%. However, only a few research groups have fabricated PSCs with an efficiency of >25%, indicating that achieving this efficiency remains uncommon. To develop the PSC industry, outstanding talent must be reserved with the latest technologies. Herein, we summarize the recent developments in high-efficiency PSCs (>25%) and highlight their effective strategies in crystal regulation, interface passivation, and component layer structural design. Finally, we propose perspectives based on current research to further enhance the efficiency and promote the commercialization process of PSCs.

Photoelectrochemical (PEC) water splitting can directly convert solar energy into hydrogen energy for storage, effectively ending the energy crisis and solving environmental problems. With their modification by many researchers, photoanodes have rapidly improved in PEC performance. Nevertheless, the poor stability of PEC water-splitting devices has not been effectively corrected, seriously hindering their practical application and large-scale commercialization. In this review, we provide a detailed introduction to the photocorrosion mechanism of photoanodes and characterizations of stability, summarizing the current research progress on the stability of metal oxide/sulfide photoanode materials. According to the specificity of each semiconductor, the corrosion mechanism and modification strategy of each photoanode are discussed in detail. Finally, we summarize the deficiencies in the current stability research and propose influencing factors and possible solutions that need to be considered in the photocorrosion research field of photoanodes. This review can provide a reference for the stability research of photoanodes based on metal oxides and sulfides, especially for the design of efficient and stable metal sulfide-based photoanodes.

Formamidine (FA)-based perovskite solar cells (PSCs) are promising candidates for photoelectric conversion devices due to their excellent optoelectronic properties. However, the instability of perovskites, especially moisture instability, remains one of the biggest obstacles to the commercialization of perovskite devices. Therefore, it is very important to explore and target the effect of moisture on FA-based perovskites to prevent this effect and improve device stability. Herein, we studied the degradation process of commonly used FA-based perovskite films by X-ray diffraction and scanning electron microscopy characterization and analyzed the reasons for their humidity-induced degradation. Subsequently, we further adopted a strategy by adding methylammonium bromine powder into a PbI₂ precursor solution to prepare a seed solution in a two-step preparation process to enhance the performance and stability of FA-based PSCs. Finally, the degradation rate of the obtained perovskite film was significantly slowed down under high humidity compared to that of perovskite films prepared by a two-step method without applying a seed solution. The corresponding device achieved a remarkable power conversion efficiency of 23.22%, and the efficiency of this device showed no attenuation after 900 h of exposure to air.

Methylammonium lead halide perovskites have been reported to be promising candidates for high-performance photodetectors. However, self-powered broadband ultraviolet-visible-near infrared (UV-Vis-NIR) photodetection with high responsivity is difficult to achieve in these materials. Here, we demonstrate, for the first time, a novel trilayer hybrid photodetector made by combining an n-type Si wafer, TiO₂ interlayer and perovskite film. By precisely controlling the thickness of the TiO₂ layer, enhanced separation and reduced recombination of carriers at the Si–perovskite interface are obtained. As a result, perovskite film, when combined with a low-bandgap Si, extends the wavelength range of photo response to 1, 150 nm, along with improved on/off ratio, responsivity, and specific detectivity, when compared to pristine perovskite. Results obtained in this work are comparable or even better than those reported for perovskite-based UV-Vis-NIR photodetectors. In particular, the hybrid photodetectors can operate in a self-powered mode. The mechanism of enhancement has been explored and it is found that the increased separation and reduced recombination of photogenerated carriers at the junction interface leads to the improved performance.

Lithium iron silicate (Li₂FeSiO₄) is capable of affording a much higher capacity than conventional cathodes, and thus, it shows great promise for high-energy battery applications. However, its capacity has often been adversely affected by poor reaction activity due to the extremely low electronic and ionic conductivity of silicates. Here, we for the first time report on a rational engineering strategy towards a highly active Li₂FeSiO₄ by designing a carbon nanotube (CNT) directed three-dimensional (3D) porous Li₂FeSiO₄ composite. As the CNT framework enables rapid electron transport, and the rich pores allow efficient electrolyte penetration, this unique 3D Li₂FeSiO₄-CNT composite exhibits a high capacity of 214 mAh·g⁻¹ and retains 96% of this value over 40 cycles, thus, outstripping many previously reported Li₂FeSiO₄-based materials. Kinetic analysis reveals a high Li⁺ diffusivity due to coupling of the migration of electrons and ions. This research highlights the potential for engineering 3D porous structure to construct highly efficient electrodes for battery applications.

Photoelectrodes with a specific structure and composition have been proposed for improving the efficiency of solar water splitting. Here, a novel multijunction structure was fabricated, with Si nanowires as cores, ZnIn₂S₄ nanosheets as branches, and TiO₂ films as sandwiched layers. This junction exhibited a superior photoelectrochemical performance with a maximum photoconversion efficiency of 0.51%, which is 795 and 64 times higher than that of a bare Si wafer and nanowires, respectively. The large enhancement was attributed to the effective electron–hole separation and fast excited carrier transport within the multijunctions resulting from their favorable energy band alignments with water redox potentials, and to the enlarged contact area for facilitating the electron transfer at the multijunction/electrolyte interface.

Among the important optoelectronic devices, ultraviolet (UV) photodetectors show wide applications in fire monitoring, biological analysis, environmental sensors, space exploration, and UV irradiation detections. Research interest has focused on the utilization of one-dimensional (1D) metal oxide nanostructures to build advanced UV photodetectors through various processes. With large surface-to-volume ratio and well-controlled morphology and composition, 1D metal oxide nanostructures are regarded as promising candidates as components for building photodetectors with excellent sensitivity, superior quantum efficiency, and fast response speed. This article reviews the latest achievements with 1D metal oxide nanostructures reported over the past five years and their applications in UV light detection. It begins with an introduction of 1D metal oxide nanostructures, and the significance, key parameters and types of photodetectors. Then we present several kinds of widely-studied 1D nanostructures and their photodetection performance, focusing on binary oxides with wide-bandgap (such as ZnO, SnO₂, Ga₂O₃, Nb₂O₅, and WO₃) and ternary oxides (such as Zn₂SnO₄, Zn₂GeO₄, and In₂Ge₂O₇). Finally, the review concludes with our perspectives and outlook on future research directions in this field.