Comparative Study on Methods for the Synthesis of CsPbBr 3 Perovskite Nanoparticles at Room Temperature
- PDF / 1,439,519 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 67 Downloads / 215 Views
ONICS
Comparative Study on Methods for the Synthesis of CsPbBr3 Perovskite Nanoparticles at Room Temperature A. V. Ivanchikhinaa, b, * and K. S. Pundikova, c aInstitute
of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow oblast, 142432 Russia bMoscow Institute of Physics and Technology, Dolgoprudnyi, Moscow oblast, 141701 Russia c Lipetsk State Technical University, Lipetsk, 398055 Russia *e-mail: [email protected] Received May 10, 2020; revised May 10, 2020; accepted May 12, 2020
Abstract—Comparative studies of three different methods for the synthesis of colloidal CsPbBr3 nanoparticles at room temperature have been carried out. Stability of these techniques with respect to the experimental conditions and ratio of the concentrations of mixed precursors have been determined, and the effect of the conditions on the average size of the nanoparticles, their sedimentation, and aggregative stability have been examined. Keywords: perovskite, perovskite nanoparticles, methods for the synthesis of perovskite quantum dots, luminescence of perovskite nanoparticles, CsPbBr3, Cs4PbBr6 DOI: 10.1134/S0018143920050070
INTRODUCTION Perovskite crystal structures have attracted significant interest in a variety of optoelectronic applications in recent years. Perovskite is a rare mineral for the Earth’s surface, calcium titanate CaTiO3, which was first discovered in 1839 in the Urals Mountains (Russia) by the German scientist Gustav Rose and named after the Russian mineral collector, Count L.A. Perovskii. Various compounds with a crystal lattice similar to that of CaTiO3 are commonly called perovskites and denoted by the stoichiometric formula ABX3, where A and B are cations and X is an anion (Fig. 1).
Halide perovskites are compounds in which A is the methylammonium (CH3NH+3), the formamidium (FA+), or the Cs+ cation; B is the Pb2+ or the Sn2+ cation; and X is one of the halide anions Cl−, Br−, and I−. For the currently most popular compound CsPbBr3, the Goldschmidt factor is 0.815 [3]. It was found that the presence of a cation with a large radius (such as cesium Cs+) in the A position sig-
If cation B is much smaller than cation A, perovskite has a cubic lattice and coordination numbers 12, 6, and 8 for ions A, B, and X, respectively. To assess the stability of the crystal structure of perovskites, the Goldschmidt tolerance factor is used:
τ=
А
А X
А
А X X
rA + rB , 2 ( rB + rX )
X
B X
where rA, rB, and rX are the ionic radii of the corresponding ions. For an ideal cubic lattice, τ ≈ 1. If τ < 0.9 or τ > 1.1, the structure of the crystal lattice can be orthorhombic or tetragonal [1]. For the structure of the cesium–lead–halogen composition, which is studied in this paper, τ ≈ 0.7–0.9, the existence of cubic, tetragonal, orthorhombic, and monoclinic crystal systems is possible [2]. 328
А
А X
А
А
Fig. 1. Perovskite ABX3 type crystal lattice.
COMPARATIVE STUDY ON METHODS FOR THE SYNTHESIS
Method А
Method В CsBr + PbBr + OA + nOCA in DMF
Method С HBr + PbBr2 in DMF Cs+
Aceton
Data Loading...
