Rongkun Zheng

Following the unprecedented improvements in photovoltaic power conversion efficiencies, 3D/2D perovskite heterostructures have emerged as a powerful platform for high-performance perovskite photodetectors by leveraging complementary physicochemical properties. Their key advantage lies in synergistic interfacial band engineering, which integrated the strong light absorption of 3D perovskites with the spectral tunability and enhanced environmental stability of 2D counterparts, while improving charge-carrier transport efficiency. This synergy enables simultaneous optimization of key photodetector performance metrics, including detectivity, response speed, and operational stability. However, achieving precise, scalable, and cost-effective control over interfacial phase purity and crystallographic orientation remains a major challenge for commercialization. This review critically summarizes recent advances in interfacial engineering strategies for 3D/2D perovskite photodetectors. We first introduce the fundamentals and key performance parameters of photodetectors, followed by an overview of the advantages of perovskites as active materials. We then discuss both the theoretical and experimental advantages of 3D/2D heterostructures relative to single-phase 3D and 2D perovskites. Furthermore, we examine the main fabrication methods and analyze how heterointerface optimization enhances device performance. Finally, the remaining challenges and future directions toward high-performance, stable, and scalable 3D/2D perovskite photodetectors are outlined.

Silver nanowire (Ag NW) transparent conductive electrodes (TCEs) are promising for flexible electronics, but their applications are limited by poor thermal, photochemical, and chemical stability under harsh conditions. Here, we report Ag@Au core–shell NWs fabricated by epitaxially depositing an ultrathin, conformal Au shell onto high‐aspect‐ratio Ag NWs, effectively protecting the Ag core while preserving the conductive network. Compared with pristine Ag NW networks, the Ag@Au films exhibited significantly enhanced stability. The sheet resistance increased by less than 50% after thermal treatment at 200°C for 40 min, whereas bare Ag NW films showed a 606% increase. Under UV/O ₃ exposure, Ag NW films lost conductivity within 7.5 min, while Ag@Au films remained conductive beyond 10 min. In corrosive media, resistance increases were reduced from 451% to 85% in Na ₂ S and from 152% to 25% in NH ₃ ·H ₂ O solutions. After 6 × 10 ³ bending cycles, Ag@Au films showed only a 13% increase in resistance, compared to 289% for Ag NWs. Furthermore, Ag@Au‐based Joule heaters demonstrated lower resistance drift while maintaining comparable heating performance. These results highlight a robust strategy for stable transparent conductive networks in harsh‐environment flexible electronics.

All-inorganic halide perovskites have attracted significant attention for photodetection applications owing to their excellent optical and electrical properties, together with superior stability against chemical and radiation-induced degradation. Here, we report a facile solution-processing strategy for synthesizing large-area (up to 8.5 × 8 cm2) single-crystal-like CsPbBr3 films. Compared with bulk single crystals, these films offer advantages including large-area scalability, controllable thickness, and improved device integration while maintaining comparable optoelectronic properties. The as-prepared films exhibit a low trap density of 9.4 × 1010 cm-3, enabling a high carrier mobility of 66 cm2 V-1 s-1 and an outstanding mobility–lifetime product of up to 1.02 × 10-3 cm2 V-1. Photodiodes based on these films demonstrate excellent performance, including a high responsivity of 432 mA W-1, a detectivity of 2.4 × 1011 Jones, and a fast response time of 44 ms. Importantly, the large-area devices exhibit excellent uniformity in responsivity and detectivity across different regions. Moreover, the devices retain over 90% of their initial responsivity after one month of storage under N2 conditions and remain operational after 5 days in air. Stable photocurrent responses under varying laser intensities for up to 20 min further confirm their excellent operational stability.

Flexoelectricity, the generation of electric polarization by a strain gradient, has recently emerged as a powerful tool for manipulating photoconversion processes in a wide range of materials. This review systematically examines how strain‐gradient‐induced flexoelectric fields can enhance and tailor both photovoltaic and photoconductive responses, overcoming fundamental limitations of conventional optoelectronic designs. We review key advances across material platforms, including oxide and halide perovskites, two‐dimensional semiconductors, with emphasis on mechanisms such as band‐structure modulation, carrier separation, and photoconductance tuning under mechanical strain. Experimental demonstrations of giant flexo‐photovoltaic coefficients, strain‐programmable photodetectors, and flexo‐enhanced photocatalytic systems are then surveyed, alongside theoretical insights into the coupling between flexoelectric polarization and photoexcited carriers. Despite the promising progress, significant challenges remain in quantitatively disentangling intrinsic flexoelectric contributions, implementing scalable and controllable strain engineering strategies, and ensuring mechanical robustness under operational conditions. Looking forward, we outline emerging pathways, including freestanding thin films, micro‐structured strain architectures, and multifunctional device integration, which harness flexoelectricity to enable adaptive, efficient, and mechanically responsive photoconversion systems for next‐generation energy and sensing technologies.

Lead halide perovskites hold great promise for photovoltaics and optoelectronics, yet ion migration continues to challenge their long-term stability. Here, combining first-principles calculations and machine learning molecular dynamics, we unravel the interplay between perovskite octahedral lattice dynamics and energy barrier associated with ion migration. Our results show that B-site substitution, particularly with alkaline-earth and lanthanide elements, notably strengthens lattice interactions, restrains octahedral oscillation, and increases iodine-migration barriers, outperforming the commonly used A-site and X-site substitutions and interstitial doping. Moreover, the enhanced barrier aligns with the geometric factor of μτ (tolerance-octahedral product), underlining the superior effectiveness of co- and multiple-element B-site doping in lattice stabilization and ion migration suppression. Experimental validation with exemplary hysteresis-free Eu-Ca–doped perovskite single crystals demonstrates remarkable improvements in ambient stability and transport properties. These findings highlight B-site engineering as an effective microstructural strategy for controlling ion migration, with important implications for stable and lead-reduced perovskite devices.

A defect-engineered BiVO ₄ catalyst with oxygen vacancies on an SnO ₂ skeleton enhances charge separation, light absorption, and glycerol activation, enabling efficient DHA production under neutral PEC conditions for sustainable biomass valorization.

Highly textured single-crystal-like perovskite films for large-area, high-performance photodiodes

Two-dimensional (2D) metal halide perovskites are renowned for their tunable optoelectronic properties and superior stability compared to their three-dimensional counterparts. However, their efficiency in photovoltaic devices has been hampered due to the disordered alignment of quantum wells and a tendency for in-plane growth. Herein, we proposed a de-templated crystallization strategy to control the crystallization kinetics of 2D perovskites via developing a stable intermediate phase in two-step deposition. By precisely adjusting the chemical interactions in the precursor solutions and driving the crystallization process, we successfully eliminate the templated in-plane growth near the liquid-air interface and promote the formation of highly out-of-plane orientated crystals, with the grain size exceeding 5 μm and carrier lifetime increased by four-fold. The optimized 2D perovskite solar cell achieves a high-power conversion efficiency (PCE) of 21.16% and a short-circuit current of 23.71 mA cm⁻². Additionally, the devices demonstrate remarkable stability, with a PCE decrease of less than 5% after exposure to 65 ± 10% humidity for 1100 hours, operation at 85 °C for 1077 hours, or continuous illumination for 1045 hours.