Effectiveness of Solvent Vapor Annealing on Optoelectronic Properties for Quasi-2D Organic–Inorganic Hybrid Perovskite Light-Emitting Diodes
Xiaojuan Sun, Changfeng Han, Zhe Liu, Ling Xu, Jinpeng Li, Haomiao Yu, Kai Wang
Abstract
The postprocessing method such as solvent vapor annealing (SVA) can be effective for the fabrication of high-quality quasi-two-dimensional (quasi-2D) organic–inorganic hybrid perovskites (OIHPs). A complete study of the method on optoelectronic properties for a quasi-2D OIHP, such as PEA2(MAPbBr3)n−1PbBr4, is still deficient. Herein, four commonly used organic solvents were adopted for the fabrication of perovskite light-emitting diodes (PeLEDs). N,N-Dimethylformamide (DMF) is found to be one of the best candidates. The corresponding PeLED produces a maximum luminesce and an efficiency of approximately 3.1 × 104cd/cm2 and 11.4cd/A at Vapp = 3.7 V, respectively. The turn-on voltage (Vturn-on) is measured to be approximately 2.1 V. The SVA-DMF-processed PEA2(MAPbBr3)n−1PbBr4 is studied from three critical angles, namely, the film crystallinity, electron–hole recombination dynamics, and electrically induced dielectric response. Incorporating the method has merits on the enhancement of electron–hole recombination, in terms of reductions on the recombination resistance, crystalline grain size, and dielectric constant. Despite this, a remarkable suppression of the full width at half maximum of the electroluminescence for high color purity can be obtained. The appropriate use of SVA via the organic solvent has advantage in promoting self-organization of the low-dimensional hybrid material in a thermodynamically favorable manner.