Facile Synthesis of CsPbX3 Perovskite Quantum Dots via an Open-Air Solution Strategy

In this work, a facile solution based on the supersaturated crystallization principle combined with an ion exchange strategy was employed for the preparation of all-inorganic lead halide perovskite CsPbX3 quantum dots (X = Cl, Br, I, and their combinations) under an ambient atmosphere. As the results showed, with the progression of Br-Cl and Br-I ion exchange, the green emission of pure CsPbBr3 gradually turned to cyan and blue, yellow, and red, respectively. Thus, the emission featured a broad wavelength range from 472 nm to 638 nm. With regard to the morphology, the as-synthesized quantum dots were all spherical and monodisperse, and the crystal size increased from the blue to the red samples. Furthermore, the chemical composition investigated by energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) confirmed the successful Br-Cl or Br-I ion exchange, and the obtained samples were expressed as CsPbBr1.9Cl1.1, CsPbBr2.1Cl0.9, CsPbBr3, CsPbBr1.7I1.3, and CsPbBr0.9I2.1 for blue, cyan, green, yellow, and red samples, respectively. In future work, the as-synthesized samples will be investigated for use in an optoelectronic device application.