Nanoimprint lithography (NIL) is a widely used, high-throughput fabrication technique for photonic devices. However, its reliability is typically compromised by inevitable imperfections introduced during the demolding process. Topological photonics, which harnesses topologically non-trivial structures to support defect-robust photonic states, offers a promising solution to this limitation. Here, we demonstrate a topological laser fabricated via single-step nanoimprinting onto colloidal perovskite nanocrystals. This laser supports multiple higher-order topological corner states (HOTCS), with the topological protection provided by the structure effectively mitigating fabrication imperfections that typically arise during nanoimprinting. This robustness enables the reliable detection of these HOTCS, a feat that is particularly challenging to achieve within the visible spectrum. Overall, we established topological photonics as a viable pathway for enhancing the reliability of NIL-based manufacturing, providing a scalable and practical route for the mass production of topological lasers with low-index materials.

Despite huge progress accomplished in perovskite light-emitting diodes (PeLEDs), the electroluminescence performance of blue PeLEDs lags far behind, constraining the widespread application of PeLED technology for vibrant full-colour displays1-5. The wider bandgaps of blue emitters require higher working voltages of corresponding electroluminescent devices, intensifying the octahedral instability of perovskites with ionic nature6,7. Here we report efficient and stable PeLEDs with saturated blue emissions by constructing hydrogen-bonding networks formed within perovskite and at the interface using isomeric molecules. The O-benzylhydroxylamine hydrochloride (OBCl) between the hole transport layer and the emitter acts as hydrogen-bonding donor, binding to the perovskite inorganic framework, which enhances the perovskite structural stability and decreases the hole energy barrier due to the large dipole moment. The isomeric N-benzylhydroxylamine hydrochloride (NBCl) added into the perovskite provides acceptor and donor sites for forming hydrogen bonding with the OB+ and the perovskite. The isomeric molecular hydrogen bonding reinforces the preferential orientation of perovskite films induced by OB+ interfacial molecules, improving the carrier mobility and further enhancing material stability. We demonstrate, as a result, blue PeLEDs with external quantum efficiencies of 16.8% at 463 nm and 22.0% at 468 nm, as well as significantly improved device stability, representing state-of-the-art performance among pure- and deep-blue PeLEDs.

Quantum dot (QD) superlattices offer collective optoelectronic properties distinct from disordered solids1-4, but their integration into high-resolution display devices remains elusive because of difficulties in achieving spatially defined, structurally coherent thin films. Here we report a scalable strategy for fabricating pixelated perovskite QD (PeQD) superlattice thin-film arrays that feature in-plane long-range order, vertical confinement and precise spatial patterning. By engineering rhombic dodecahedral CsPbBr3 nanocrystals with robust surface termination by a ligand-fluoride co-stabilization approach, we direct the formation of hexagonally close-packed superlattice films using capillary liquid-bridge confined assembly. These superlattice films exhibit reduced energetic disorder and enhanced electronic coupling. When integrated into light-emitting diodes (LEDs), the electrically driven PeQD superlattices yield an external quantum efficiency of 30.9%, high luminance of 117,144 cd m-2 and pixel densities of up to 5,080 pixels per inch. The devices show an extrapolated operational half-lifetime (T50) of 12,411 h at 100 cd m-2-more than 1,000-fold longer than previously reported pixelated PeQD LEDs. Moreover, we demonstrate the direct integration of patterned superlattices onto a commercial thin-film transistor backplane to construct a 1.85-inch active-matrix display with full greyscale control and video playback ability. These results establish colloidal QD superlattices as a viable material platform for next-generation high-resolution, stable and efficient perovskite displays.

Two-dimensional (2D) tin (Sn)-based perovskites are promising lead-free emitters for red light-emitting diodes (LEDs), but their intrinsically low carrier mobility and poor film morphology severely limit large-area performance. Here, we introduce a one-step antisolvent-assisted approach that disperses amino-functionalized multi-walled carbon nanotubes (CNTs) along the grain boundaries of phenethylammonium tin iodide (PEA2SnI4) films. The CNTs provide conductive pathways that accelerate carrier diffusion, while their ammonium groups regulate crystallization and improve film uniformity. Transient absorption microscopy and transport measurements confirm that carrier conduction is more than doubled in CNT-modified films. As a result, large-area (150 mm2) PEA2SnI4 LEDs achieve a maximum external quantum efficiency of 2.35% and a peak luminance of 5028 cd m-2, exceeding the threshold for outdoor-readable displays. This grain-boundary engineering strategy directly addresses the transport and morphology limitations of 2D Sn-based perovskites and establishes a scalable route to high-performance, lead-free optoelectronics.

Whispering-gallery-mode (WGM) lasers and vertical-cavity surface-emitting lasers (VCSELs) are pivotal for optical communications and optoelectronic sensing. However, their further development has been hindered by challenging fabrication processes and the high thresholds typically required for single-mode operation. Here we demonstrate a viable route to address these limitations by integrating CdSe/CdSeS core/alloy crown colloidal quantum wells (CQWs) with a hollow-core silica microsphere-based mode-selection strategy. The solution-processability of CQWs substantially simplifies cavity fabrication and eliminates the need for stringent high-temperature vacuum conditions. Using the proposed microsphere-mode-selection approach, we achieve green single-mode lasing under 355 nm nanosecond pulsed excitation (7 ns, 20 Hz) with an ultralow threshold of 510 nJ cm-2, which is, to the best of our knowledge, the lowest reported value to date for CQWs-based laser. Moreover, without altering the cavity architecture, we realize flexible multichannel switching between single-mode and multimode lasing in VCSELs. This work offers a practical solution to key challenges faced by conventional laser technologies and is expected to enable broad applications in optoelectronics, particularly in optical communications and high-precision sensing.

Quantum dots (QDs) have emerged as promising candidates for next-generation display owing to their exceptional optoelectronic properties. However, despite substantial advancements in QD synthesis, the blue-emitting QDs, especially heavy-metal-free blue ones, still underperform compared with their red and green counterparts. ZnSeTe QDs offer a viable ecofriendly alternative for blue emissions, but their performance is limited by spectrum broadening (linewidth >20 nm) and structural instability. These issues stem from compositional inhomogeneity, which is primarily induced by Te aggregation during synthesis. Recently, we realized the synthesis of homogeneous quaternary-alloyed ZnSeTeS QDs through a synergistic strategy of reactivity modulation and isoelectronic control. This Protocol enables precise bandgap tuning in the blue spectral region (450-475 nm) by controlling the Te ratio, while ensuring high color purity and stability of QDs. Furthermore, the as-prepared ZnSeTeS QDs exhibit outstanding electroluminescence performance, with a peak external quantum efficiency of 24.7% and half-life of 29,600 h at 100 cd cm-2, and demonstrate strong potential for applications such as solid-state lighting and bioimaging owing to their high stability and low toxicity. Here we detail a synthesis Protocol for ZnSe0.94Te0.03S0.03/ZnSe/ZnS core/shell/shell QDs via a hot-injection method using zinc carboxylate and anionic phosphine precursor, systematically outlining the design and preparation of precursors and QDs, post treatments (including purifications) and characterization methods, including time-resolved photoluminescence spectroscopy. The entire process typically requires 11-12 h for QD synthesis and 6 h for characterizations, demanding only accessible chemistry knowledge and routine colloidal synthesis techniques.

Despite substantial advances in green and red metal halide perovskite light-emitting diodes (PeLEDs), blue PeLEDs, particularly deep-blue ones (defined as Commission International de l’Eclairage y coordinate (CIEy) less than 0.06) that meet the latest Rec. 2020 colour gamut standard, lag dramatically behind owing to a severe phase segregation-induced electroluminescent spectral shift and low exciton utilization in broadened bandgap perovskite emitters. Here we propose a multivalent immobilization strategy to realize high-efficiency and spectrally stable deep-blue PeLEDs by introducing a polyfluorinated oxygen-containing molecule. Systematic experiments and extensive 5,000 fs ab initio molecular dynamics simulations reveal that a crucial role of the multivalent effect stemming from three kinds of interaction of hydrogen bond (F···H–N), ionic bond (F–Pb) and coordination bond (C=O:Pb) with perovskite is to synergistically stabilize the perovskite phase and enhance exciton radiative recombination. The resultant exciton concentration and exciton recombination rate of the deep-blue perovskite emitter are increased by factors of 1.66 and 1.64, respectively. In this context, our target PeLEDs demonstrate a peak external quantum efficiency of up to 15.36

White light-emitting diodes based on single-component quantum dots (sc-WQLEDs) have gained great attention owing to their low operating voltage and the high spectral stability of their emission. However, their performance presently lags far behind that of state-of-the-art white organic LEDs owing to a lack of efficient white quantum dot emitters. Creating self-trapped excitons in semiconductor quantum dots is a promising approach to producing broadband white emission. However, such emitters generally suffer from poor charge transport and structural instability. Here we accomplish controllable synthesis of core/shell structured ZnSe/ZnS quantum dots with efficient white emission through combining a sharp excitonic blue emission with a broadband yellow self-trapped exciton emission owing to local lattice softening of ZnSe cores by heterovalent doping with halogen ions. We reveal that the self-trapped excitons confined in the surrounding ZnSe covalent-bond matrix can generate strong and stable yellow emission with minimal reduction of the excitonic blue emission and charge transport capability of ZnSe. On the basis of this approach, we demonstrate highly efficient, heavy-metal-free WQLEDs with a maximum external quantum efficiency up to 15% (average 10.5 +/- 2.6%), a luminance of over 26,000 cd m-2 as well as exceptional device operational lifetime with T50 exceeding 2,500 h at an initial luminance of 100 cd m-2.

Metal halide perovskite nanocrystals (PeNCs) have emerged as promising materials for next-generation light-emitting diodes (PeLEDs) due to their outstanding optical properties. However, synthesis challenges such as rapid crystallization often introduce defects that degrade device performance. Herein, a dual-ligand approach employing trioctylphosphine oxide (TOPO) and phenylphosphinic acid (PPIA) is introduced to coordinate Pb2+ ions, effectively slowing the crystallization process and minimizing defect formation. The obtained PeNCs exhibit a high photoluminescence quantum yield (PL QY) of 93%. Additionally, the PPIA ligand enhances electrical conductivity via pi-electron resonance, enabling more efficient charge transport in FAPbBr3 films. As a result, the optimized PeLEDs achieve a peak external quantum efficiency (EQE) of 24.2% and a luminance of 32 840 cd m-2, significantly outperforming the control devices, which exhibit an EQE of 12.1% and a luminance of 1577 cd m-2. Furthermore, the operational lifetime of the optimized PeLEDs is 5.3 times longer than that of the control devices. These findings offer a promising pathway for advancing the performance and stability of PeLEDs.

Low‐dimensional metal halides have emerged as promising anti‐counterfeiting materials. However, achieving a multi‐mode and multi‐color anti‐counterfeiting system in metal halides remains challenging. In this study, copper‐halide (TBP) 2 Cu 4 Br 6 (TBP + = C 16 H 36 P + ) single crystals are synthesized using a cooling crystallization method, which exhibits efficient dual‐band emissions (542 and 708 nm), large Stokes shifts (282 and 330 nm), and a high photoluminescence quantum yield (PLQY) of 92.7% for 542 nm. These exceptional properties are attributed to the unique 0D structure of (TBP) 2 Cu 4 Br 6 single crystals, which facilitates the formation of two different self‐trapped excitons (STEs). Furthermore, based on (TBP) 2 Cu 4 Br 6 , a multi‐mode and multi‐color digital anti‐counterfeiting system integrated is designed with Morse code information encryption, demonstrating promising applications in information security and anti‐counterfeiting. This work not only illustrates an emitter in copper halides but also paves the way for achieving multi‐mode and multi‐color anti‐counterfeiting systems.

Tin (Sn)-based perovskites have made notable advances with external quantum efficiency of over 20%, but still exhibit low electroluminescence brightness insufficient for outdoor displays. Here, it is demonstrated that compact phenethylammonium tin iodide (PEA2SnI4) films with an intact crystal structure can offer high luminance by optimizing the perovskite crystallization rate simultaneously with engineering the grain surface. Ammonium thiocyanate is added to the precursor solution to generate the film with PEA2SnIxSCN4-x and NH4I after spin-coating. Sn2+ and SCN- have a strong interaction that slows crystallization to improve PEA2SnI4 crystal quality. During the subsequent annealing, I- from NH4I replaces SCN- in PEA2SnIxSCN4-x by forming thiourea, which can escape from the film to leave intact PEA2SnI4 crystals. It is found that the optimized PEA2SnI4 emitting layers can provide outstanding film coverage, high crystallinity, low trap state density, and superior photophysical performance. Consequently, an impressive brightness of 8285 cd m-2 for pure red electroluminescence is achieved, the first report of Sn-based perovskite light-emitting diodes that meet outdoor display requirements.

The growing potential of low-dimensional metal-halide perovskites as conversion-type cathode materials is limited by electrochemically inert B-site cations, diminishing the battery capacity and energy density. Here, we design a benzyltriethylammonium tellurium iodide perovskite, (BzTEA)2TeI6, as the cathode material, enabling X- and B-site elements with highly reversible chalcogen- and halogen-related redox reactions, respectively. The engineered perovskite can confine active elements, alleviate the shuttle effect and promote the transfer of Cl- on its surface. This allows for the utilization of inert high-valent tellurium cations, eventually realizing a special eleven-electron transfer mode (Te6+/Te4+/Te2-, I+/I0/I-, and Cl0/Cl-) in suitable electrolytes. The Zn||(BzTEA)2TeI6 battery exhibited a high capacity of up to 473 mAh g-1Te/I and a large energy density of 577 Wh kg-1 Te/I at 0.5 A g-1, with capacity retention up to 82% after 500 cycles at 3 A g-1. The work sheds light on the design of high-energy batteries utilizing chalcogen-halide perovskite cathodes. Functional perovskites are promising energy storage materials but have received little attention. Here, authors report a tellurium iodide perovskite as a conversion-type material enabling eleven-electron redox in chloride containing aqueous electrolytes for zinc batteries.

Guest editors Guohua Jia, Hongxia Wang, Xuyong Yang, Lina Quan and Yun Liu introduce this cross-journal themed collection on nanomaterials for a sustainable future: from materials to devices and systems.

This study examines the mediating effect of subjective housing quality between housing conditions and mental health, using survey data from ten Chinese mega-cities. The results from multi-level linear regression models show that housing areas are highly associated with subjective housing quality and that renters have lower levels of subjective housing quality than homeowners. At the community level, the age of housing tends to diminish its subjective quality, while a lower plot ratio is associated with more favorable evaluations of housing conditions. Surprisingly, educational resources in proximity to housing are negatively associated with subjective housing quality. Subjective housing quality is closely linked to mental health. Additionally, the results show that home ownership significantly strengthens the association between subjective housing quality and mental health. Namely, the mediating effect of subjective housing quality on the relationship between housing conditions and mental health is stronger for homeowners than for renters.

High-quality single crystals (SCs) are crucial for advanced photoelectronic devices like light-emitting diodes (LEDs), lasers, and photodetectors. Zero-dimensional organic antimony-based metal halides, such as Gua3SbX6, offer great promise due to their unique structure and high photoluminescence quantum yield (PLQY). However, producing large-sized SCs remains challenging, because the multi-site nucleation leads to parasitic crystal formation, which consumes the abundant precursors. In this study, we utilized zinc acetate as an additive to cultivate centimeter-scale Gua3SbBr6 SCs. Zn2+ ions robustly coordinate with Br- ions, effectively retarding their participation in the SC seed formation and suppressing multi-site nucleation. These optimized SCs were used to fabricate a white light-emitting diode (WLED) with a high color rendering index (CRI) of 89 and a maximum power efficiency of 48.6 lm/W, significantly outperforming conventional WLEDs. This study not only deepens our understanding of crystal growth dynamics but also addresses a key challenge, paving the way for high-performance, eco-friendly photoelectronic devices using Gua3SbBr6 SCs.

Metal halide perovskites have demonstrated remarkable progress in optoelectronic applications, including solar cells and light-emitting diodes (LEDs). However, the long-term stability of perovskite LEDs (PeLEDs) remains a critical challenge, impeding their practical applications and commercialization. Herein, we regulate the growth kinetics of perovskites in liquid-solid stages by introducing 2,3,4,5, 6-pentafluorophenylphosphonic acid (PFBPA) into the precursor solution. The PFBPA molecules will create a protective passivation layer by coordinating with uncoordinated lead (Pb2+) on the perovskite surface, which regulates the growth of perovskite crystals during the liquid-solid stages and results in the formation of uniform perovskite films with reduced grain size. Moreover, the coordination of PFBPA with Pb2+ also improves the moisture resistance of perovskites, favoring the operational stability of devices. The resulting PeLED devices achieved a maximum brightness of 12426 cd m-2, a peak external quantum efficiency (EQE) of 22.6%, and a remarkable operational stability with a half-lifetime exceeding 1187 hours at initial luminance of 100 cd m-2.

The electroluminescence of quantum dot (QD) light-emitting diodes (QLEDs) has undergone significant enhancement to fulfil the prerequisites for commercialization in next-generation display. Nevertheless, the blue QLEDs still suffer from subpar device performance compared to red and green counterparts. The deep energy level of blue QDs leads to inferior hole injection capability. Additionally, the small potential barrier between the core and shell facilitates carrier in blue QDs coupling with sulfur dangling bonds on the QD surface. Herein, phenethylammonium chloride (PEACl), a dipole molecule, is introduced to modify the surface of blue QDs. The replacement of long-chain oleic acid ligands with Cl- ions improves carrier transport, while the NH3 + group of PEACl passivates surface sulfur defects. Additionally, the large dipole moment of PEACl upshifts the energy levels, thereby enhancing hole injection efficiency in the devices. Consequently, the resulting devices based on PEACl-modified ZnCdSe/ZnCdS/ZnS QDs exhibit a record external quantum efficiency of 23.8%, a peak luminance of 42,724 cd m-2, and an extrapolated operational lifetime of 22,180 h at 100 cd m-2, significantly outperforming the control devices. This work offers a promising approach to enhance the efficiency and stability of blue QLEDs for advanced display applications.

Tin (Sn)-based perovskite light-emitting diodes (PeLEDs) have emerged as a promising candidate for next-generation displays because of their eco-friendliness, exceptional optoelectronic properties, and cost-effective solution processability. However, their electroluminescence performance still lags behind their lead (Pb) counterparts, primarily due to the undesired Sn2+ oxidation to Sn4+ and the rapid crystallization of Sn-based perovskite, resulting in high defect density as well as poor film quality. Herein, we reported a competitive antioxidation strategy by utilizing a phosphorus ylide, namely (triphenylphosphoranilidene) acetaldehyde (TPPA), to suppress the oxidation of Sn2+ and regulate the growth kinetics, simultaneously. The TPPA with highly active polar phosphorus-carbon bonds can be oxidized prior to Sn2+, and their large steric hindrance can slow down the crystallization process of tin-based perovskite. Moreover, the main product from the oxidation reaction, namely triphenylphosphine oxide (TPPO), can further passivate defects by coordinating with SnI6 octahedra. The resulting Sn-based perovskite film exhibits enhanced optical properties and uniform, dense morphology. Leveraging these improvements, the optimized PeLED delivers pure-red light emission with Commission Internationale de L’Eclairage (CIE) color coordinates of (0.69, 0.30), an external quantum efficiency (EQE) of 8.1% and maximum luminance of 672 cd m-2. This work provides a facile route to enhance the overall performance of Sn-based PeLEDs.

Quasi-two-dimensional (quasi-2D) perovskites have shown great potential in the application of light-emitting diodes (LEDs) due to their large exciton binding energy, tunable bandgaps, and solution processability. However, the heavily used spacer cations will cause serious deprotonation reactions in quasi-2D perovskite films, leading to lattice collapse and abundant defect states, which are notorious for fabricating efficient perovskite LEDs (PeLEDs). Herein, we develop an in situ proton-feeding strategy to restrain the deprotonation process in quasi-2D perovskites by introducing a proton-rich Lewis base, namely trifluoromethyl nicotinic acid (TFNA), into the perovskite precursor solutions. The TFNA molecules can donate protons during the growth of quasi-2D perovskite films to simultaneously compensate the deprotonated spacer cations, passivate the defects states by coordinating with Pb2+, and improve structural stability by forming hydrogen bonds with organic spacers. This leads to an enhanced photoluminescence quantum yield of 78.8%. The resulting red-emitting quasi-2D PeLEDs achieved a high external quantum efficiency of 27.5% at 660 nm, accompanied by a 3.5-fold enhancement of the operational lifetime (T50) compared to that of the reference device based on pristine perovskite. This work deepens the understanding of the crystallization of quasi-2D perovskite films and provides a new avenue to improve the PeLEDs performance.