Interface modification has been demonstrated as an effective means to enhance the performance of perovskite solar cells. However, the effect depends on the anchoring mode and strength of the interfacial molecules, which determines whether long-term robust interface for carrier viaduct can be achieved under operational light illumination. Herein, we select squaric acid (SA) as the interfacial molecule between the perovskite and SnO₂ layer and propose a self-regulated bilateral anchoring strategy. The unique four-membered ring conjugated structure and dicarboxylic acid groups facilitate stable hydrogen bonds and coordination bonds at both SnO₂/SA and SA/PbI₂ interfaces. The self-transforming property of SA enables the dynamic bilateral anchoring at the buried interface, ultimately releasing residual stress and constructing a stable interfacial molecular bridge. The results show that SA molecular bridge not only can effectively inhibit the generation of diverse charged defects but also serves as an effective electron transport pathway, resulting in improved power conversion efficiency (PCE) from 23.19 to 25.50% and excellent stability at the maximum power point. Additionally, the PCEs of the flexible and large-area (1 cm²) devices were increased to 24.92% and 24.01%, respectively, demonstrating the universal applicability of the bilateral anchoring to PSCs based on different substrates and larger area.

In recent years, two-dimensional (2D) type-II van der Waals (vdW) heterojunctions have emerged as promising candidates for high-performance photodetectors. However, direct experimental evidence confirming the enhancement of photoelectric properties by the heterojunction’s type and structure remains scarce. In this work, we present flexible photodetectors based on individual GaSe and MoS₂, as well as a vertically stacked type-II GaSe/MoS₂ vdW heterojunction on polyethylene terephthalate (PET) substrate. These devices demonstrate outstanding responsivities and rapid response speeds, ensuring stable and repeatable light detection. It is notable that the GaSe/MoS₂ heterojunction photodetector exhibits the highest on-off ratio and fastest response speed, attributed to the formation of type-II band alignment. Furthermore, the GaSe/MoS₂ heterojunction photodetector maintains robust stability even in a bent state, highlighting remarkable flexibility. This work exemplifies the type-II vdW heterojunctions in enhancing photoelectric properties through direct in-situ experimentation, laying the groundwork for practical applications of 2D flexible photodetectors.

Perovskite solar cells have witnessed a surge in interest as a promising technology for low-cost, high-efficiency photovoltaics with certified power conversion efficiencies beyond 25%. However, their commercial development is hindered by poor stability and nonradiative losses that restrict their approach to the theoretical efficiency limit. Using ab initio nonadiabatic molecular dynamics, we demonstrate that nonradiative charge recombination is suppressed when the iodide in formamidinium lead iodide (FAPbI₃) is partially replaced with pseudohalide anions (SCN^-, BF₄^-, and PF₆^-). The replacement breaks the symmetry of the system and creates local structural distortion and dynamic disorder, decreasing electron-hole overlap and nonadiabatic electron-vibrational coupling. The charge carrier lifetime is found to increase with increased structural distortion and is the longest for PF₆^-. This work is fundamentally relevant to the design of high-performance perovskite materials for optoelectronic applications.

Self-powered flexible MoS₂ photodetectors show an excellent overall performance, and their self-driving force originates from asymmetric vdW gaps.

Lithium iron phosphate (LiFePO4) with an olivine-type structure has garnered great interest due to its electrochemical activity. It is considered one of the most promising cathode materials for lithium-ion batteries because of its high discharge platform, large theoretical capacity, and excellent cycling performance and stability. However, the typical crystal structure of LiFePO4 restricts the formation of efficient electron conduction pathways and hampers the embedding and removal motion of lithium ions, resulting in low electron conductivity and a low ion diffusion rate. The experimental results show that element doping can reduce the activation energy of diffusion, increase the diffusion rate of lithium ions, improve the rate capability of lithium-ion batteries, and contribute to the improvement of its conductivity. In this work, the electronic structure and diffusion mechanism of a S/Co/Mn co-doped LiFePO4 system are systematically studied. The introduction of S, Co, and Mn atoms leads to the formation of impurity bands, resulting in a significant reduction in the bandgap from 3.593 eV to 0.190 eV, which is beneficial for improving the conductivity of LiFePO4. Moreover, the diffusion activation energy of lithium ions decreases from 0.73 eV to 0.34 eV, and the diffusion rate of lithium ions increases from 2.7 × 109 cm/s to 1.0 × 1016 cm/s. These results demonstrate that co-doping of S, Co, and Mn can effectively enhance the conductivity and diffusion rate of lithium ions in LiFePO4, providing a reliable reference for improving the electrochemical performance of lithium iron phosphate.