Multivalent effect enables efficient and stable deep-blue perovskite LEDs
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Improved radicchio seedling growth under CsPbI3 perovskite rooftop in a laboratory-scale greenhouse for Agrivoltaics application
Agrivoltaics, integrating photovoltaic systems with crop cultivation, demands semitransparent solar modules to mitigate soil shadowing. Perovskite Solar Cells (PSC) offer competitive efficiency, low fabrication costs, and high solar transmittance, making them suitable for agrivoltaic applications. However, the impact of PSC light filtering on plant growth and transcriptomics remains underexplored. This study investigates the viability and agronomic implications of the growth of radicchio seedlings (Cichorium intybus var. latifolium) in laboratory-scale greenhouses integrating Perovskites-coated rooftops. Eu-enriched CsPbI3 layers are chosen to provide semi-transparency and phase stability while radicchio has limited size and grows in pots. Despite the reduced light exposure, radicchio seedlings exhibit faster growth and larger leaves than in the reference, benefiting from specific spectral filtering. RNA-sequencing reveals differential gene expression patterns reflecting adaptive responses to environmental changes. Simulations of full PSC integration demonstrate a positive energy balance in greenhouses to cover annual energy needs for lighting, irrigation, and air conditioning.
Surfactant-induced hole concentration enhancement for highly efficient perovskite light-emitting diodes
It is widely acknowledged that constructing small injection barriers for balanced electron and hole injections is essential for light-emitting diodes (LEDs). However, in highly efficient LEDs based on metal halide perovskites, a seemingly large hole injection barrier is usually observed. Here we rationalize this high efficiency through a surfactant-induced effect where the hole concentration at the perovskite surface is enhanced to enable sufficient bimolecular recombination pathways with injected electrons. This effect originates from the additive engineering and is verified by a series of optical and electrical measurements. In addition, surfactant additives that induce an increased hole concentration also significantly improve the luminescence yield, an important parameter for the efficient operation of perovskite LEDs. Our results not only provide rational design rules to fabricate high-efficiency perovskite LEDs but also present new insights to benefit the design of other perovskite optoelectronic devices.
Efficient and stable near-infrared InAs quantum dot light-emitting diodes
Visible quantum dot light-emitting diodes have satisfied commercial display requirements. However, near-infrared counterparts considerably lag behind due to the inferior quality of near-infrared quantum dots and limitations in device architecture suitable for near-infrared electroluminescence. Here, we present an efficient strategy using zinc fluoride to balance ZnSe shell growth across different core quantum dot facets, producing highly regular InAs/InP/ZnSe/ZnS quantum dots with near-unity quantum yield. Moreover, we develop a method of in-situ photo-crosslinking blended hole-transport materials for accurate energy level modulation. The crosslinked hole-transport layers enhance hole transfer to the emitting layer for balanced carrier dynamics in quantum dot light-emitting diodes. The resulting near-infrared quantum dot light-emitting diodes exhibit a peak external quantum efficiency of 20.5%, a maximum radiance of 581.4 W sr−1 m−2 and an operational half-lifetime of 550 h at 50 W sr−1 m−2. This study represents a step towards practical application of near-infrared quantum dot light-emitting diodes.
Fluorine-modified passivator for efficient vacuum-deposited pure-red perovskite light-emitting diodes
Vacuum-deposited perovskite light-emitting diodes (PeLEDs) have demonstrated significant potential for high-color-gamut active-matrix displays. Despite the rapid advance of green PeLEDs, red ones remain a considerable challenge because of the inferior photophysical properties of vacuum-deposited red-light-emitting materials. Here, a rationally designed fluorine-modified phosphine oxide additive was introduced to in-situ passivate vacuum-deposited perovskites. The highly polar 2-F-TPPO incorporated perovskite films demonstrated enhanced photoluminescence quantum yield (PLQY), suppressed defects, and improved crystallinity. When implemented as active layers in PeLEDs, an external quantum efficiency (EQE) of 12.6% with an emission wavelength of 640 nm is achieved, which was 6 times higher compared to the previously reported most efficient vacuum-deposited red PeLEDs (EQE below 2%). Our findings lay the foundations for the further exploration of high-performance vacuum-deposited PeLEDs toward full-color perovskite displays.
Perovskite-driven solar C2 hydrocarbon synthesis from CO2
Photoelectrochemistry (PEC) presents a direct pathway to solar fuel synthesis by integrating light absorption and catalysis into compact electrodes. Yet, PEC hydrocarbon production remains elusive due to high catalytic overpotentials and insufficient semiconductor photovoltage. Here we demonstrate ethane and ethylene synthesis by interfacing lead halide perovskite photoabsorbers with suitable copper nanoflower electrocatalysts. The resulting perovskite photocathodes attain a 9.8% Faradaic yield towards C2 hydrocarbon production at 0 V against the reversible hydrogen electrode. The catalyst and perovskite geometric surface areas strongly influence C2 photocathode selectivity, which indicates a role of local current density in product distribution. The thermodynamic limitations of water oxidation are overcome by coupling the photocathodes to Si nanowire photoanodes for glycerol oxidation. These unassisted perovskite–silicon PEC devices attain partial C2 hydrocarbon photocurrent densities of 155 µA cm−2, 200-fold higher than conventional perovskite–BiVO4 artificial leaves for water and CO2 splitting. These insights establish perovskite semiconductors as a versatile platform towards PEC multicarbon synthesis.
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