Guangguang Huang

The scalable synthesis of perovskite nanocrystals (PNCs) with monodispersity and high emission efficiency remains a significant challenge, primarily limited by the inherent constraints of flask‐based batch synthesis in handling large volumes. Here, we propose a novel microscale continuous droplet‐in‐flow synthesis (µ‐CDFS) of PNCs stabilized by zwitterionic ligands. This synergy, arising from the spatial and temporal separation of droplet‐based reactors and a cross‐locked PNC‐ligand surface coordination, ensures exceptional mixing efficiency and consistency. Consequently, our approach enables the scalable production of high‐quality PNCs, delivering a continuous output of 0.8 g h ^{− 1} per channel, a narrow size distribution (σ _r < 14%), and a photoluminescence quantum yield (PLQY) exceeding 97%. Furthermore, high‐throughput ligand screening is also performed via autonomous flow experimentation, and the emission of PNCs is precisely tuned across the visible region (453–753 nm) via on‐demand halide anion exchange, establishing a robust platform for the accelerated discovery of PNCs.

In practical applications, fluorescent perovskite quantum dots (PQDs) must exhibit high efficiency, stability, and processibility. So far, it remains a challenge to synthesize PQDs with stable dispersibility in tailorable monomers both before and after photocuring. In this work, a novel strategy of UV‐induced two‐step thiol‐ene “click chemistry” is proposed to prepare PQDs with these attributes. The first step aims to epitaxially grow a shell around the PQD core to ensure stable dispersibility in a thiol‐ene monomer solution. The second step is to achieve stable dispersibility in the photocured thiol‐ene matrixes for multiform manufacturing processes. The tailorable PQDs (T‐PQDs) not only have the highest photoluminescence quantum yield (PLQY) to ≈100% for green emission and over 96% for red emission, but also exhibit remarkable stability under severe conditions, including “double 85” aging, water exposure, and mechanical stress. Moreover, their exceptional processability allows for various processing techniques, including slot‐die coating, inkjet printing, direct‐laser writing, UV‐light 3D printing, nanoimprinting, and spin coating. The high efficiency and stability of T‐PQDs facilitate their multiform manufacturing for a wide range of applications.

Post‐synthetic halide anion exchange is considered a “double‐edged sword” for perovskite nanocrystals (PNCs), which offer unique access to color tunability while bringing about surface defects. Herein, a novel surface cation cross‐locking (SCCL) strategy is proposed to achieve the anion‐exchanged CsPbX ₃ PNCs (X is Cl, Br, I) with non‐destructive emissions. This is achieved using a dendritic ligand of Pentaerythritol tetrakis (3‐mercaptopropionate) (PETMP) as a surface cross‐locker, which can form the multiple coordination to the surface Pb cation of octahedral [PbX ₆ ] ⁴⁻ during the fast halide anion exchange via four end‐thiolates and four side‐carboxylates. As a result, the red‐ and blue‐emitting anion‐exchanged CsPbX ₃ PNCs exhibit high photoluminescence quantum yield (PLQY) values of >97%, close to the parent green‐emitting CsPbBr ₃ PNCs. Moreover, the “on‐demand” synthesis of anion‐exchanged CsPbX ₃ PNCs is also performed via autonomous robotic in‐flow experimentation. This work provides a new general post‐synthetic way for the full‐color CsPbX ₃ PNCs with compositions that are inaccessible via direct synthetic routes.

Cesium zirconium halide (e.g., Cs2ZrCl6:Te or CZCT) perovskites have garnered significant interest due to their unique optical properties. However, there have been no reports of CZCT perovskite nanoparticles (PNPs) that simultaneously offer high efficiency and thermal stability. Here, a comprehensive defect suppression strategy is reported to achieve CZCT PNPs with these attributes. First, the inner defects of CZCT perovskite microcrystals (PMCs) are minimized by controlling crystallization kinetics precisely. Second, the PNPs are obtained from PMCs via top‐down fabrication, and the surface defects of PNPs are passivated via the hydroxyl groups of alkyl‐terminated silica‐oligomer shell (ASO). The resulting CZCT@ASO PNPs show the highest photoluminescence quantum yield (PLQY) of 96% and high thermal stability among the reported conventional CZCT emitters. Finally, white light‐emitting diodes (WLEDs) are integrated by using CZCT@ASO PNPs as the down‐color converters, achieving a color coordinate of (0.31, 0.33) and a color rendering index of 86. These results demonstrate that core/shell CZCT@ASO PNPs have great potential as phosphors for lighting applications.

In the modern era, structural health monitoring (SHM) is critically important and indispensable in the aerospace industry as an effective measure to enhance the safety and consistency of aircraft structures by deploying a reliable sensor network. The deployment of built-in sensor networks enables uninterrupted structural integrity monitoring of an aircraft, providing crucial information on operation condition, deformation, and potential damage to the structure. Sustainable and durable piezoelectric nanogenerators (PENGs) with good flexibility, high performance, and superior reliability are promising candidates for powering wireless sensor networks, particularly for aerospace SHM applications. This research demonstrates a self-powered wireless sensing system based on a porous PVDF-based PENG, which is prominently anticipated for developing auto-operated sensor networks. Our reported porous PVDF film is made from a flexible piezoelectric polymer (polyvinylidene fluoride (PVDF)) and inorganic zinc oxide (ZnO) nanoparticles. The fabricated porous PVDF-based PENG demonstrates ~ 11 times and ~ 8 times enhancement of output current and voltage, respectively, compared to a pure PVDF-based PENG. The porous PVDF-based PENG can produce a peak-to-peak short-circuit current of 22 µA, a peak-to-peak open-circuit voltage of 84.5 V, a peak output power of 0.46 mW (P=V_oc/2×I_sc/2), and peak output power density of 41.02 µW/cm2 (P⁄A). By harnessing energy from minute vibrations, the fabricated porous PVDF-based PENG device (area of A= 11.33 cm2) can generate sufficient electrical energy to power up a customized wireless sensing and communication unit, and transfer sensor data every ~ 4 minutes. The PENG can generate sufficient electrical energy from an automobile car vibration, which reflects the scenario of potential real-life SHM systems. We anticipate this high-performance porous PVDF-based PENG can act as a reliable power source for the sensor networks in aircraft, which minimizes potential safety risks.

There is an urgent demand in the industry for the development of compact, flexible, and sustainable power sources for self-powered internet of things (IoT) micro/nano devices. One of the most promising routes is to harness environmental energy through piezoelectric nanogenerators (PNGs). A novel, self-assembled, highly porous perovskite/polymer (polyvinylidene fluoride (PVDF) in this case) composite film was developed for fabricating high-performance piezoelectric nanogenerators (PNGs). The macroscopic porous structure can significantly enlarge the bulk strain of the piezoelectric composite film, which leads to a ≈5-fold enhancement in the strain-induced piezo potential. In addition, the novel hybrid halide perovskites (HHP)–formamidinium lead bromine iodine (FAPbBr₂I) material can improve the conductivity of the final composite film due to its enhanced permittivity, providing a ≈15-fold amplification of the output current. Using these highly-efficient perovskite/polymer PNGs (P-PNGs), a peak output power density of 10 μW cm⁻² (across a resistance of 7 MΩ) was obtained to run a self-powered integrated wireless electronic node (SIWEN). The P-PNG application was then extended to real-life scenarios including wireless data communication between the nanogenerators and personal electronics, efficient energy harvesting from automobile vibrations and also from biomechanical motion. This P-PNG based on a low-temperature full-solution synthesis approach, may initiate a paradigm shift by opening the realms of flexible PNGs as sustainable power sources.

The passivation of defects at perovskite grain boundaries (GB) is crucial in achieving highly efficient and stable perovskite solar cells. Unlike the widely used additive passivation method where a mixture of additives and perovskite precursor is used for preparing perovskite films, we herein developed a new defect post-healing method via dip-coating trioctylphosphine oxide (TOPO) ligands on pre-fabricated carbon-based mesoscopic perovskite solar cells (MPSCs). Since perovskites have formed before post-healing, TOPO ligands are selectively adsorbed onto the exposed perovskite surface and hence have little influence on charge extraction of interfaces. The defects are post-healed via O atoms in PO bonds coordinated to halide-deficient sites, leading to an enhancement of the power conversion efficiency (PCE) from 11.0% to 12.8%. Moreover, due to the three hydrophobic long chain alkyls in TOPO, the humidity stability of the device has also been improved simultaneously.