CsPbBr₃ QD/AlO_x Inorganic Nanocomposites with Exceptional Stability in Water, Light, and Heat

Abstract

Herein, the assembly of CsPbBr 3 QD/AlO x inorganic nanocomposites,b yu sing atomic layer deposition (ALD) for the growth of the amorphous alumina matrix (AlO x ), is described as an ovel protection scheme for such QDs.T he nucleation and growth of AlO x on the QD surface was thoroughly investigated by miscellaneous techniques, which highlighted the importance of the interaction between the ALD precursors and the QD surface to uniformly coat the QDs while preserving the optoelectronic properties.T hese nanocomposites show exceptional stability towardsexposure to air (for at least 45 days), irradiation under simulated solar spectrum conditions (for at least 8h), and heat (up to 200 8 8Cin air), and finally upon immersion in water.T his method was extended to the assembly of CsPbBr x I 3Àx QD/AlO x and CsPbI 3 QD/AlO x nanocomposites,w hich were more stable than the pristine QD films. Figure 3. Stability studies with CsPbBr 3 QD/AlO x nanocomposites obtained by performing100 ALD cycles on 60 nm thick QD films. A) PL over 45 days of storage under ambient conditions. B) Photographs taken under UV illumination (l = 365 nm) after 1hof soaking in water.C)PL properties after 8hof photosoaking under solar spectrum irradiation at 10 mWcm À2 .D )XRD spectra recorded after annealing in air at 200 8 8C. For the graphs showing PL data, the typical error range is I err = AE 5% and l err = AE 1nm. Angewandte Chemie Communications Angewandte Chemie Communications

Ceramic-like stable CsPbBr3 nanocrystals encapsulated in silica derived from molecular sieve templates

“…A routine strategy is to coat the NCs with inert shells or incorporate them into barrier matrixes, which can isolate CsPbX 3 NCs from moisture and oxygen, and also prevent ion migration and the induced inter-particles fusing 9 . For example, the stabilities of CsPbX 3 NCs have been improved by encapsulating them into inorganic oxides (SiO 2 10 , Al 2 O 3 11 , SiO 2 /Al 2 O 3 12 , TiO 2 13 , ZrO 2 14 ), mesoporous materials (mesoporous silica 15 , metal − organic frameworks 16 ), polymer matrixes (polystyrene 17 , polymethyl methacrylate 18 , polyvinylidene fluoride 19 ), inorganic salts (NaNO 3 20 , NH 4 Br 21 ), and shell formation (CsPbBr 3 / CsPb 2 Br 5 22 , CsPbBr 3 /Cs 4 PbBr 6 23 , CsPbBr 3 /Rb 4 PbBr 6 24 ). However, these shells or barrier matrixes can only slow down the degradation of CsPbX 3 NCs by the external environmental factors, and their stability is still much worse than the ceramic phosphors.…”

Improved photoelectric performance of all-inorganic perovskite through different additives for green light-emitting diodes

“…Meanwhile, a dense alumina may be coated on the perovskite layer to form a dense protection, which can keep the stable device in water, air and light. 38 The CsPbBr 3 -PEO-PVP type perovskite thin lm are contributed to the improvement of performance of perovskite LEDs, which opens up a new promising avenue for future thin lm LED development. It can be expected that the results will provide some help in developing polymer additive-assisted perovskite LEDs with high performance.…”

Monochromatic LEDs based on perovskite quantum dots: Opportunities and challenges

“…However, encapsulation of perovskite NCs in different inorganic matrixes can be a powerful strategy to enhance the NC stability and the protection against the above‐mentioned conditions such as high temperatures or humidity. Various inorganic matrixes such as SiO 2 , TiO 2 , and alumina have been reported . The investigations of the thermal stability of the perovskite QDs in display applications are crucial for applying them in optoelectronic devices such as LEDs.…”