Highly Luminescent and Ultrastable CsPbBr₃ Perovskite Quantum Dots Incorporated into a Silica/Alumina Monolith

Abstract

We successfully prepared QDs incorporated into as ilica/alumina monolith (QDs-SAM) by as imple sol-gel reaction of an Al-Si single precursor with CsPbBr 3 QDs blended in toluene solution, without adding water and catalyst. The resultant transparent monolith exhibits high photoluminescence quantum yields (PLQY) up to 90 %, and good photostability under strong illumination of blue light for 300 h. We show that the preliminary ligand exchange of didodecyl dimethyl ammonium bromide (DDAB) was very important to protect CsPbBr 3 QDs from surface damages during the sol-gel reaction, whichn ot only allowed us to maintain the original optical properties of CsPbBr 3 QDs but also prevented the aggregation of QDs and made the monolith transparent. The CsPbBr 3 QDs-SAM in powder form was easily mixed into the resins and applied as color-converting layer with curing on blue light-emitting diodes (LED). The material showed ahigh luminous efficacy of 80 lm W À1 and an arrowe mission with afull width at half maximum (FWHM) of 25 nm.

Highly Efficient and Water‐Stable Lead Halide Perovskite Quantum Dots Using Superhydrophobic Aerogel Inorganic Matrix for White Light‐Emitting Diodes

“…[50] Figure S1 (Supporting Information) shows S-AIMs with irregular shapes and randomly distributed particle size at 0.5-50 µm, which are www.advmattechnol.de further confirmed by the scanning electron microscopy (SEM) images in Figure 3b. [23,27,51] S-AIMs can effectively solve this issue since the PQD mean size of 22 nm ( Figure S4, Supporting Information) is comparable to the S-AIM mean pore size of 20 nm ( Figure S5, Supporting Information). These random pore structures and the rough surface lead to a combined effect, preventing the ambient moisture from penetrating into the S-AIMs, and as will be discussed in the following, serve for protecting the PQDs.…”

“…[4] Particularly, PQDs suffer from low chemical and optical stabilities, resulting in their fast degradation under exposure to moisture, heat, and light irradiance. [13,14] Current research efforts therefore aim at enhancing the stability of PQDs by covering them in inorganic materials, including CdS, [15] zeolite, [16,17] glass, [18,19] CaF 2 , [20] Al 2 O 3 , [21][22][23] SiO 2 , [24][25][26][27][28][29] and TiO 2 . [13,14] Current research efforts therefore aim at enhancing the stability of PQDs by covering them in inorganic materials, including CdS, [15] zeolite, [16,17] glass, [18,19] CaF 2 , [20] Al 2 O 3 , [21][22][23] SiO 2 , [24][25][26][27][28][29] and TiO 2 .…”

Perovskite Quantum Dots and Their Application in Light‐Emitting Diodes

“…Copyright 2017, Wiley‐VCH). f) Optical image of QDs‐SAM powder (Reproduced with permission . Copyright 2017, Wiley‐VCH).…”

Pure Bromide‐Based Perovskite Nanoplatelets for Blue Light‐Emitting Diodes

“…These results suggested that a complete replacement of OLA and OA by DDAB was achieved. Similar ligand exchange route was employed by Li's group . They found that the balanced external environment of CsPbBr 3 nanocrystal inks would be disrupted during the SiO 2 /Al 2 O 3 sol–gel process.…”

“…c) Photographs of CsPbBr 3 nanocrystals and DDAB‐treated CsPbBr 3 nanocrystals after adding di‐sec‐butoxyaluminoxytriethoxysilane (DBATES) into solutions and their corresponding monolith with different content of perovskites. Reproduced with permission . Copyright 2017, Wiley‐VCH.…”