Quasi-two-dimensional perovskite light-emitting diodes (quasi-2D PeLEDs) are emerging as high-potential candidates for new generation of wide-color gamut displays due to their simple, low-cost solution process, and high color purity. However, the luminescence performance of quasi-2D perovskite films is severely limited by dispersed phase distribution and excessive defect density, which are caused by excessive diffusion of nucleation sites during the perovskite growth stage. Here, the benzylphosphonic acid (BPA) molecule, owing to its strong P–O–Pb bond energy sites and strong electronegativity to PEA⁺, can aggregate lead-halide octahedron to grow high-dimensional phases, avoiding scattered low-dimensional phases (n = 1). The continuous gradient phase distribution will be beneficial to smooth carrier injection and effectively suppress the leakage current in PeLEDs. Meanwhile, the introduction of phosphonic acid groups will fill the vacancies of Pb ions and reduce non-radiative recombination. As a result, the maximum external quantum efficiency (EQE) of PeLEDs can be increased from 8% to 20.6% with a 514 nm light emission and a 21 nm full-width half maximum, and the device lifetime (T₅₀) is nearly 6-fold of the pristine sample. In addition, this strategy is also suitable for other wavelength. For example, in blue light, performance improvement is also realized that the maximum EQE of 8% and the luminance increased from 1045 to 5264 cd/m². These results provide a feasible strategy to regulate the phase distribution and passivate the defects of quasi-2D perovskites.

Quaternary Ag-In-Ga-S (AIGS) quantum dot (QD) is considered a promising, spectral-tunable, and environmentally friendly luminescent display material. However, the more complex surface defect states of AIGS QDs resulting from the coexistence of multiple elements lead to a low (< 60%) photoluminescence quantum yield (PLQY). Here, we develop a novel convenient method to introduce Z-type ligands ZnX₂ (X = Cl, Br, I) for passivating the surface defects of AIGS QDs to dramatically enhance the PLQY and stability without affecting the crystalline structure and morphology. Results show that the addition of ZnCl₂ during the purified process of AIGS QDs leads to a 3-fold increase of PLQY (from 28.5% to 87%). Impressively, the highest PLQY is up to a recorded value of 92%, which is comparable to typical heavy metal QDs. Exciton dynamics studies have shown that the rapid annihilation process of excitons in treated QDs is inhibited. We also confirm that the improvement in PLQY is a result of the effective passivation of the non-coordinating atom on the QD surface by building a new bonding between sulfur dangling and Zn²⁺. The realization of high PLQY will further promote the application of AIGS QDs in luminescent displays.

Developing light-emitting diodes (LEDs) with the merits of low driving and high brightness has always been attractive. Considering the carrier dynamic process under electroexcitation, the built-in potential (V_bi) represents the moment that the photons start to be produced in a LED. However, it has not been carefully studied and discussed. Here, we observed that by employing an interface regulation strategy to enhance hole concentration, the V_bi of quantum dot LEDs (QLEDs) can be reduced. Combined with the characterization methods of Mott–Schottky (MS) and scanning Kelvin probe microscopy (SKPM), the key indicator of V_bi on driving voltage for QLEDs is confirmed. Profiting from the reduction of V_bi, a record-breaking ultra-low turn-on voltage of 2.2 V (@1 cd/m²) is achieved in a blue QLED. The blue QLED shows an advantage of high brightness under low driving voltages, i.e., 1000 cd/m²@3.10 V and 5000 cd/m²@3.88 V. This work proposes a reference strategy to predict and analyze the driving voltage issue, which is beneficial to facilitating the development of low-driving QLEDs in the future.

The development of multifunctional materials and synergistic applications of various functions are important conditions for integrated and miniaturized equipment. Here, we developed asymmetric MXene/aramid nanofibers/polyimides (AMAP) aerogels with different modules using an integrated molding process. Cleverly asymmetric modules (layered MXene/aramid nanofibers section and porous MXene/aramid nanofibers/polyimides section) interactions are beneficial for enhanced performances, resulting in low reflection electromagnetic interference (EMI) shielding (specific shielding effectiveness of 2483 (dB·cm³)/g and a low R-value of 0.0138), high-efficiency infrared radiation (IR) stealth (ultra-low thermal conductivity of 0.045 W/(m·K) and IR emissivity of 0.32 at 3–5 μm and 0.28 at 8–14 μm), and excellent thermal management performances of insulated Joule heating. Furthermore, these multifunctional AMAP aerogels are suitable for various application scenarios such as personal and building protection against electromagnetic pollution and cold, as well as military equipment protection against infrared detection and EMI.

Narrowband photodetectors as specific spectral sensing pixels have drawn intense attention in multispectral detection due to their distinct characteristic of filter-free spectrum discrimination, in which the emerging halide lead perovskites witness a booming development in their performance and wavelength-selectivity from blue to near-infrared light. However, the challenge in integrating perovskite narrowband photodetectors on one chip imposes an impediment on practical application. In this work, the combination of laser-direct-writing and ion exchange is proposed as an efficient way to fabricate high-definition colorful sensing array with perovskite narrowband photodetector unit as pixel. Under laser irradiation, the photolysis of halocarbon solvent (CHCl₃, CH₃CH₂I, etc) releases the halide ions, which brings the ion exchange and gives rise to slow-varying bandgap in single perovskite photoactive film. This ion exchange can be controlled via laser irradiation time and focus point, thus enabling precisely engineerable bandgap. By optimizing the process, it is successfully applied to develop patterned perovskite narrow blue and green photodetectors array with a high-definition of ~ 53 ppi. We believe this result will make a great step forward to integrate multifunctional perovskite devices on one chip, which will pave the way for perovskite optoelectronic device to the commercial application.

Controllable anisotropic growth of perovskite nanocrystals (NCs) is challenging since it is difficult to separate the nucleation and growth processes. Here, a two-step nucleation strategy is proposed to control the binding interaction between surface ligands and NCs, resulting in facet-induced coordination competition. Oleic acid as surface activated ligand leads to the formation of defective lead bromine octahedron, and the binding interaction between 4-dodecylbenzenesulfonic acid and lead atoms promotes the formation of two kinds of binding interactions. Based on this strategy, the anisotropic growth of CsPbBr₃ nanoplatelet (NPLs) with adjusted length from 11.4 to 24 nm, and the evolution of NPLs from stacked to tongue-shaped have been realized. Elemental line scan reveals the sulfur atoms mainly distribute at the edge of NPLs. Furthermore, binding energy calculation and experimental results illustrate the coordination competition of different binding interaction on specific facets induces the anisotropic growth of NPLs. Importantly, strong emission anisotropy of highly ordered NPLs with polarization ratio up to 0.58 is illustrated. This work not only deepens our understanding of the controllable synthesis of perovskite NCs, but also provides a reference for the regulation of light emitting diode and soler cells.

Full-spectrum underwater optical communication (UOC) is of great significance for major strategic needs including resource development, scientific exploration, and homeland security. As the core of the full-spectrum UOC system, photodetectors (PDs) are plagued by stringent requirements including a broadband response, intrinsic water resistance, and a high detectivity. In this work, two-dimensional (2D) halide perovskites (HPs) and corresponding PDs are constructed by stearamine (SA), representing the rarely explored long-chain aliphatic amine series, to own waterproofness, ultralow noise, and superior optoelectronic performance, which consequently enable a high suitability for UOC. By dimensionality and composition modulations to extend the absorption onset down to 1.5 eV, a broadband response covering the entire transmission window of water (> 1.55 eV) for full- spectrum UOC can be obtained. Besides, featuring a high responsivity of 3.27 A·W⁻¹, a peak external quantum efficiency (EQE) of 630%, fast rise/decay times of 0.35 ms/0.54 ms, a superior detectivity up to 1.35 × 10¹² Jones and the capability to distinguish various waveforms and light intensities, the PDs present sensitive and persistent photoresponse underwater. As a result, proof-of-concept wireless transmission of ASCII codes in water is demonstrated.

The rapid development of information technology has led to an urgent need for devices with fast information storage and processing, a high density, and low energy consumption. Memristors are considered to be next-generation memory devices with all of the aforementioned advantages. Recently, organometallic halide perovskites were reported to be promising active materials for memristors, although they have poor stability and mediocre performance. Herein, we report for the first time the fabrication of stable and high-performance memristors based on inorganic halide perovskite (CsPbBr₃, CPB). The devices have electric field-induced bipolar resistive switching (ReS) and memory behaviors with a large on/off ratio (> 10⁵), low working voltage (< 1 V) and energy consumption, long data retention (> 10⁴ s), and high environmental stability, which are achieved via ZnO capping within the devices. Such a design can be adapted to various devices. Additionally, the heterojunction between the CPB and ZnO endows the devices with a light-induced ReS effect of more than 10³ with a rapid response speed (< 1 ms), which enables us to tune the resistance state by changing the light and electric field simultaneously. Such multifunctional devices achieved by the combination of information storage and processing abilities have potential applications for future computing that transcends traditional architectures.