Meeting High Stability and Efficiency in Hybrid Light‐Emitting Diodes Based on SiO₂/ZrO₂ Coated CsPbBr₃ Perovskite Nanocrystals

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‐Pot Synthesis of CsPbX3 (X = Cl, Br, I)@Zeolite: A Potential Material for Wide‐Color‐Gamut Backlit Displays and Upconversion Emission

“…First, CsPbX 3 @zeolite is prepared by a one‐step method, which is similar to the hot injection method reported previously. [ 21 ] Commonly, oleic acid (OA) and oleylamine (OAm) serve as ligands to generate CsPbX 3 NCs, while octahedral zeolite acts as a cladding material providing a growth space for CsPbX 3 NCs. High‐quality CsPbX 3 @zeolite powder was obtained by further centrifugation and purification.…”

“…Currently, different encapsulation strategies have been proposed to enhance the tolerance of CsPbX 3 NCs to water and thermal conditions. For example, CsPbX 3 NCs are prepared: i) with a glass matrix via traditional melt quenching at high temperature; [ 13 ] ii) through simple mixing with porous materials; [ 14,15 ] iii) in situ synthesis in polymers; [ 16,17 ] iv) with an inorganic polymer matrix by the sol–gel method; [ 18,19 ] v) with a multiple‐encapsulation strategy with different packaging materials, [ 20–22 ] and so on. Nevertheless, there are many restrictions to the above methods, such as i) the preparation of perovskite CsPbX 3 glasses needs to be carried out in a high‐temperature environment, which leads to energy consumption; ii) when a large amount of NCs solution is compounded with polymer film, the luminescence performance of CsPbX 3 NCs is affected due to their agglomeration; iii) simple hybrid packaging is not ideal for improving the tolerance of perovskite to the environment.…”

Recent Progress on Synthesis, Characterization, and Applications of Metal Halide Perovskites@Metal Oxide

“…In 1845, the French chemist J. J. Ebelmen mixed SiCl 4 with ethanol to form tetraethoxysilane (TEOS) and a gel was formed during hydrolyzing in wet air. [73] Currently, this method is mostly used to fabricate the shell coating with SiO 2 , [74][75][76][77][78][79][80][81][82][83][84][85][86] TiO 2 , [84,87,88] ZrO 2 , [70] Al 2 O 3 /SiO 2 , [69] SiO 2 /ZrO 2 [89] around the surface of the MHPs core.…”

Photocatalytic Hydrogen Production by Stable CsPbBr3@PANI Nanoparticles in Aqueous Solution

“…In general, encapsulation with waterproof nanoshells is a straightforward strategy to improve the stability of the CsPbX 3 NCs [12,13] . To date, many water‐resisting materials were mostly chosen as the nanoshell materials, such as SiO 2 , [14–17] polymethylmethacrylate (PMMA), [18,19] polystyrene (PS), [20] etc.…”