No abstract

Significant advances are realized in perovskite-converted hybrid light-emitting diodes (pc-HLEDs). However, long-living devices at high efficiencies still represent a major milestone with average stabilities of <200 h at ≈50 lm W −1 under low applied currents (<15 mA). Herein, a dual metal oxide-coated CsPbBr 3 @SiO 2 /ZrO 2 composite is prepared in a one-pot synthesis through the kinetic control of the sol-gel reaction, followed by a gentle drying process in air. These hybrid nanoparticles show photoluminescence quantum yields of ≈65% that are stable under temperature, ambient, and irradiation stress scenarios. This is translated to pc-HLEDs with a near-unity conversion efficiency at any applied current, high efficiencies around 75 lm W −1 , and one of the most remarkable stabilities of ≈200 and 700 h at 100 and 10 mA, respectively. In addition, the device degradation mechanism is thoughtfully rationalized comparing devices operating under ambient/inert conditions. As such, this work provides three milestones: i) a new room temperature one-pot protocol to realize the first SiO 2 /ZrO 2 metal oxide coating that effectively protects the emitting perovskite nanoparticle core, ii) one of the most stable and efficient pc-HLEDs operating under ambient condition at any applied current, and iii) new insights for the degradation of pc-HLEDs.

One great challenge for perovskite solar cells (PSCs) lies in their poor operational stability under harsh stimuli by humidity, heat, light, etc. Herein, a thermal‐triggered self‐healing polyurethane (PU) is tailored to simultaneously improve the efficiency and stability of inorganic CsPbIBr2 PSCs. The dynamic covalent disulfide bonds between adjacent molecule chains in PU at high temperatures self‐heal the in‐service formed defects within the CsPbIBr2 perovskite film. Finally, the best device free of encapsulation achieves a champion efficiency up to 10.61 % and an excellent long‐term stability in an air atmosphere over 80 days and persistent heat attack (85 °C) over 35 days. Moreover, the photovoltaic performances are recovered by a simple heat treatment.

Schematic illustration of modified g-C3N4for visible-light photocatalytic water splitting to hydrogen. The CN-DPT shows remarkably enhanced hydrogen evolution performance.