Stability Enhancement in All‐Inorganic Perovskite Light Emitting Diodes via Dual Encapsulation

Abstract

Addressing the challenge of lighting stability in perovskite white light emitting diodes (WLEDs) is crucial for their commercial viability. CsPbX3 (X = Cl, Br, I, or mixed) nanocrystals (NCs) are promising for next‐generation lighting due to their superior optical and electronic properties. However, the inherent soft material structure of CsPbX3 NCs is particularly susceptible to the elevated temperatures associated with prolonged WLED operation. Additionally, these NCs face stability challenges in high humidity environments, leading to reduced lighting performance. This study introduces a two‐step dual encapsulation method, resulting in CsPbBr3@SiO2/Al2SiO5 composite fibers (CFs) with enhanced optical stability under extreme conditions. In testing, WLEDs incorporating these CFs, even under prolonged operation at high power (100 mA for 9 h), maintain consistent electroluminescence (EL) intensity and optoelectronic parameters, with surface temperatures reaching 84.2 °C. Crucially, when subjected to 85 °C and 85% relative humidity for 200 h, the WLEDs preserve 97% of their initial fluorescence efficiency. These findings underscore the efficacy of the dual encapsulation strategy in significantly improving perovskite material stability, marking a significant step toward their commercial application in optoelectronic lighting.

In Situ Synthesis of CsPbX3/Polyacrylonitrile Nanofibers with Water-Stability and Color-Tunability for Anti-Counterfeiting and LEDs

“…Recently, inorganic cesium lead halide perovskite quantum dots (PQDs) with the molecular formula CsPbX 3 (X = Cl, Br, I) have undergone extensive research as promising next-generation optoelectronic materials due to their high photoluminescent quantum yield (PLQY), color-tunable luminescence, narrow emission bands and so on [ 1 , 2 , 3 , 4 ]. They have gained significant attention in applications such as anti-counterfeiting, photocatalysis, bioimaging, displays and lighting [ 5 , 6 ]. However, the instability of PQDs can be attributed to the lower formation energy and ionic character of chemical bonds, which render them highly sensitive to environmental factors (e.g., water, temperature or radiation), greatly limiting their practical applications in optoelectronics [ 7 , 8 , 9 ].…”

Advanced lead-free double perovskites/silica hybrid nanocrystals for highly stable light-emitting diodes

“…Recent advancements have positioned lead-free double perovskite (DP) nanocrystals (NCs) as a promising alternative to conventional lead halide perovskite NCs, offering reduced toxicity and enhanced stability under atmospheric conditions. 1–6 Applications of these materials have extended across various domains, notably in solar cells and photodetectors. 7–12 Concurrently, the enhancement of the optical properties of lead-free DP materials through ion doping has emerged as a focal point of research, 13–15 setting a foundational platform for their integration into light-emitting diodes (LEDs).…”