Low-Temperature Synthesis of High-Brightness Green-Emitting Silica-Coated CsPbBr3 and Its Application in Light-Emitting Diodes

The all-inorganic cesium lead halide perovskite CsPbBr 3 exhibits excellent optical properties such as large absorption cross-section, high fluorescence quantum yield (PLQY), and narrow emission peak. However, how to improve the stability of CsPbBr 3 quantum dots has been a major challenge for their optoelectronic application. Here, a room-temperature process for synthesizing CsPbBr 3 @SiO 2 using 3-(dimethoxymethylsilyl)propylamine (DEMSPA) as precursor is reported, being a simple and facile process without inert gas. With the help of DEMSPA, a complete shell structure formed by silane can be coated. The results of x-ray diffraction analysis, transmission electron microscopy, and high-resolution transmission electron microscopy revealed that the prepared CsPbBr 3 had good crystallinity with cubic phase structure. The luminescent properties of the products were evaluated by photoluminescence spectroscopy and fluorescence lifetime measurements. DEMSPA contains an amino group (–NH 2 ) that could promote the absorption of light. The prepared CsPbBr 3 @SiO 2 emitted an adjustable green wavelength (521 nm to 533 nm) with high PLQY. The light-emitting diode encapsulated with CsPbBr 3 @SiO 2 showed a cold-white light characteristic.