Search

The challenges of instability and surface defects in CsPbBrxI3‐x nanocrystals (NCs) pose significant limitations on their potential application in high‐performance pure‐red perovskite light‐emitting diodes (PeLEDs). Herein, a synergistic strategy of divalent cation (Zn2+) doping and anion (Te2−) passivation is proposed to solve these issues. Density functional theory analysis reveals that the synergistic effect can not only reduce the formation energy of CsPbBrxI3‐x NCs but also increase theiodide vacancy defect formation energy of CsPbBrxI3‐x NCs. Consequently, the optimized Zn2+/Te2− co‐modified CsPbBrxI3‐x NCs exhibit significantly enhanced stability with a near‐unity photoluminescence efficiency. Pure‐red PeLEDs based on these CsPbBrxI3‐x NCs possess outstanding spectral stability with a maximum external quantum efficiency and luminance of 16.1% and 1397.2 cd m−2, respectively. This synergistic strategy provides a new approach for enhancing the performance of mixed halide perovskite NCs and the corresponding optoelectronic devices. [ABSTRACT FROM AUTHOR]

The rapid advancement of self-powered perovskite photodetectors (PDs) in recent years has been hindered by numerous defects present in solution-processed perovskite polycrystalline films, significantly impacting device performance. Of particular concern is the influence of these defects on device noise, a critical parameter directly affecting detector sensitivity. This study proposes the incorporation of poly(vinylidene fluoride–trifluoroethylene) (PVT) additives into FA0.9MA0.05Cs0.05PbI3 perovskite precursor solutions to alleviate defect formation and enhance detector sensitivity. By optimizing the PVT concentration to 0.05 mg L−1, the photodetector (PD) demonstrates remarkable improvement, achieving a low noise power spectral density (0.1 pA Hz−1/2) and dark current density (2.12 nA cm−2) at zero bias. The device exhibits a notable decrease in defect density by an order of magnitude through the concurrent passivation of shallow-level defects with PVT. Additionally, the PD shows a high specific detection rate (D* = 2.8 × 1013 jones) at 700 nm, accompanied by a linear dynamic range exceeding 101 dB. This research not only advances our understanding of noise suppression mechanisms but also unveils the potential application of high-sensitivity PDs for real-time heart rate monitoring, showing promise for significant advancements in human health monitoring technology. [ABSTRACT FROM AUTHOR]

Biomass-derived carbon materials have attracted considerable attention in electromagnetic wave (EMW) absorption applications due to their advantages of low cost, light weight, and sustainability. Herein, loofah sponge-derived hierarchical porous carbon nanocomposites (HPC/Co-T) were successfully synthesized by a facile dipping and subsequent carbonization method. The combination of hierarchical porous carbon with magnetic Co nanoparticles takes advantage of the synergistic effect of dielectric loss and magnetic loss, which is a compelling route to improve impedance matching and EMW attenuation capacity. The specific surface area, carbon defects, and electromagnetic parameters of the HPC/Co-T nanocomposites are effectively regulated through carbonization temperature. The HPC/Co-700 nanocomposite annealed at 700 °C with a filler content of 15 wt % exhibits an RLmin value of −66.8 dB at a thickness of 2.4 mm. Meanwhile, a broad effective absorption bandwidth of 5.5 GHz ranging from 11.7 to 17.2 GHz can be achieved at a thickness of 2.1 mm. This work provides a strategy for the fabrication of low-cost, sustainable, lightweight, and high-performance EMW-absorbing materials from nature biomass. [ABSTRACT FROM AUTHOR]