Highly fluorescent CsPbBr3/TiO2 core/shell perovskite nanocrystals with excellent stability

Abstract

The poor stability of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals is the most impediment to its application in the field of photoelectrics. In this work, monodisperse CsPbBr3/TiO2 nanocrystals are successfully prepared by coating titanium precursor on the surface of colloidal CsPbBr3 nanocrystals at room temperature. The CsPbBr3/TiO2 nanocomposites exhibit excellent stability, remaining the identical particle size (9.2 nm), crystal structures and optical properties. Time-resolved photoluminescence decay shows that the lifetime of CsPbBr3/TiO2 nanocrystals is about 4.04 ns and keeps great stability after lasting two months in the air. Results show that the coating of TiO2 on CsPbBr3 NCs greatly suppressed the anion exchange and photodegradation, which are the main reasons for dramatically improving their chemical stability and photostability. The results provide an effective method to solve the stability problem of perovskite nanostructures and are expected to have a promising application in optoelectronic fieldsArticle highlights 1. Prepared the all-inorganic CsPbBr3/TiO2 core/shell perovskite nanocrystals by an easy method. 2. Explored its essences of PL and lifetime of the synthesized CsPbBr3/TiO2 perovskite nanocrystals. 3. CsPbBr3/TiO2 nanocrystals show the great thermal stability after the post-annealing. 4. The CsPbBr3/TiO2 nanocrystals have a high PLQY and have a promising application in solar cells.

Highly luminescent dual-phase CsPbBr3/Cs4PbBr6 microcrystals for a wide color gamut for backlight displays

“…Additionally, their unsuitability for large-scale industrial synthesis requirements is another setback. To circumvent these challenges, several approaches have been proposed, such as encapsulation in inorganic shells, including ZnS, 8 CdS, 9 TiO 2 , 10 Al 2 O 3 , 11 PbSO 4 , 12 and mesoporous silica, 13 and embedding in polymer 14 and glass 15 matrices as well as heteroepitaxial structures, including CsPbBr 3 /Cs 4 PbBr 6 16 and CsPbBr 3 /CsPb 2 Br 5 core/shell structures. 17 Nevertheless, since these integration and incorporation methods are expensive, labor-intensive, and complex, they can only be performed in the laboratory and are difficult for synthesis and optimization for large-scale production.…”

Stability and photocurrent enhancement of photodetectors by using core/shell structured CsPbBr3/TiO2 quantum dots and 2D materials

“…Also, the absorption region < 400 nm was strong because of amorphous TiO 2 and carbon residues aer TiO 2 coating. 12 The X-ray diffraction (XRD) patterns of the CsPbBr 3 QDs and CsPbBr 3 /TiO 2 are shown in Fig. 2(m).…”

“… 10 H. Chen et al demonstrated a long lifetime of CsPbBr 3 /TiO 2 nanocrystals of about 4.04 ns of photoluminescence, and it remains stable after a period of two months in air. 12 Among different phases of TiO 2 , the anatase phase of TiO 2 demonstrates higher electron extraction properties, providing an efficient pathway to transport excited electrons from QDs. Furthermore, TiO 2 can protect QDs from degradation from external factors, which is crucial for developing optoelectronic devices.…”

Recent progress and future prospects on halide perovskite nanocrystals for optoelectronics and beyond

“…Xia et al. reported the preparation of monodisperse CsPbBr 3 /TiO 2 core-shell NCs by coating titanium precursor on the surface of colloidal CsPbBr 3 NCs at room temperature ( Chen et al., 2021 ). The CsPbBr 3 /TiO 2 nanocomposites exhibit excellent stability, remaining identical particle size, crystal structures, and optical properties.…”