Controllable Synthesis of All Inorganic Lead Halide Perovskite Nanocrystals with Various Appearances in Multiligand Reaction System.

Chen Chen,Guanglan Liao,Tielin Shi,Zirong Tang,Louwen Zhang

doi:10.3390/nano9121751

Abstract

All inorganic cesium lead halide (CsPbX3, X = Cl, Br, I) perovskite nanocrystals (PNCs) exhibit promising applications in light-emitting devices due to their excellent photophysical properties. Herein, we developed a low-cost and convenient method for the preparation of CsPbX3 PNCs in a multiligand-assisted reaction system where peanut oil is applied as a ligand source. The mixed-halide PNCs with tunable optical-band gap were prepared by mixing the single-halide perovskite solutions at room temperature. The resulting PNCs had good monodispersity, with dimensions of 8–10 nm, high photoluminescence quantum yield (96.9%), narrow emission widths (15–34 nm), and tunable emission wavelength (408–694 nm), covering the entire visible spectrum. Additionally, various morphologies of PNCs, such as nanospheres, nanocubes, and nanowires, were obtained by controlling reaction temperature and time, and the amount of oleamine with multiple ligands in peanut oil potentially playing a dominant role in the nucleation/growth processes of our PNCs. Finally, the resulting CsPbBr3 PNCs were employed to develop a white light-emitting diode (WLED), demonstrating the potential lighting applications for our method.

Highlights

Over the past decade, organic—inorganic hybrid perovskite has continuously attracted research attention due to its energy applications [1,2,3,4], which has, in turn, triggered a research boom on the controllable synthesis, photophysical properties, and optoelectronic devices of lead halide perovskite [5,6,7,8,9]
Single-halide CsPbX3 perovskite nanocrystals (PNCs) were synthesized via a conventional hot-injection method, and slight modification was made according to the work reported by Kovalenko et al [10]
The selected-area electron-diffraction (SAED) pattern (Figure S3) confirmed that CsPbBr3 PNCs possessed the cubic structure of CsPbBr3 crystals with corresponding (110), (200), and (211) planes

Summary

Introduction

Organic—inorganic hybrid perovskite has continuously attracted research attention due to its energy applications [1,2,3,4], which has, in turn, triggered a research boom on the controllable synthesis, photophysical properties, and optoelectronic devices of lead halide perovskite [5,6,7,8,9]. Mixed-halide PNCs with emission wavelengths over the entire visible spectral region could be synthesized by mixing single-halide PNCs stock solutions at room temperature In such a multiligand reaction system, taking cesium lead bromine PNCs as our primary example, various morphologies of PNCs, such as nanospheres, nanocubes, and nanowires, were successfully obtained under different preparation parameters. The most important difference from previous reports was that multiple organic ligands in peanut oil affect the nucleation/growth process of nanocrystals, resulting in different morphology results compared to the reported works with similar experiment parameters This opens up a novel and effective route to achieving morphological control, which determines the emission peaks of PNCs and the scope of their practical applications [28,29,30,31]. White-light-emitting diodes (WLEDs) can be further fabricated by using green CsPbBr3 PNCs combined with red nitride phosphors and GaN blue chips

Experiment Section

Results and Discussion

Conclusions