Using mesoporous SiO2 to encapsulate CsPbBr3 nanocrystals is one of the best strategies to exploit such materials in devices. However, the CsPbBr3/SiO2 composites produced so far do not exhibit strong photoluminescence emission and, simultaneously, high stability against heat and water. We demonstrate a molten-salts-based approach delivering CsPbBr3/mesoporous-SiO2 composites with high PLQY (89 ± 10%) and high stability against heat, water, and aqua regia. The molten salts enable the formation of perovskite nanocrystals and other inorganic salts (KNO3–NaNO3–KBr) inside silica and the sealing of SiO2 pores at temperatures as low as 350 °C, representing an important technological advancement (analogous sealing was observed only above 700 °C in previous reports). Our CsPbBr3/mesoporous-SiO2 composites are attractive for different applications: as a proof-of-concept, we prepared a white-light emitting diode exhibiting a correlated color temperature of 7692K. Our composites are also stable after immersion in saline water at high temperatures (a typical underground environment of oil wells), therefore holding promise as oil tracers.
Bibliographical noteKAUST Repository Item: Exported on 2021-02-15
Acknowledgements: We acknowledge funding from the programme for research and Innovation Horizon 2020 (2014-2020) under the Marie Skłodowska-Curie Grant Agreement COMPASS No. 691185 and from the Basic Research in Science & Engineering through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2020R1C1C1009150 and 2019M3D1A1078299).