Effective High Emitting CsPbBr3 LARP Colloidal Perovskites Obtained Through Different Conditions

Abstract

In this research, three synthesis conditions of green-emitting colloidal CsPbBr₃ nanocrystals obtained by LARP are discussed. Room temperature (A-RT), low temperature air atmosphere (A-LT), and a stationary-state nitrogen flow injection at room temperature (N-RT), are described. The samples were analyzed through XRD, SEM, UV–Vis, PL, and FT-IR. A crystalline cubic phase and by products mixture were identified; an average size of 15.5 to 11 nm was calculated, being the smallest one obtained at low temperature. From SEM, it is observed that morphology is affected by the ambient conditions (i.e., A-RT and N-RT samples); the particle size decreases, showing rod-like-shaped nanoparticles. Additionally, by the UV–Vis spectra, three contributions are localized, at 510, 519, and 522 nm; this could be associated with the cubic phase/byproducts. In correlation to PL, it was possible to identify the main emission peak of each sample, which was located at 511, 519, and 522 nm for A-LT, N-RT, and A-RT, respectively, noticing a redshift probably due to the size dependence. The TRPL and PLQY are measured to analyze which mechanisms are responsible for each sample emission. Finally, to identify the presence of any organic byproduct compound, the FT-IR characterization was done.