ABSTRACT
Lead-free halide perovskite materials possess low toxicity, broadband luminescence and robust stability compared with conventional lead-based perovskites, thus holding great promise for eyes-friendly white light LEDs. However, the traditionally used preparation methods with a long period and limited product yield have curtailed the commercialization of these materials. Here we introduce a universal hydrochloric acid-assistant powder-to-powder strategy which can accomplish the goals of thermal-, pressure-free, eco-friendliness, short time, low cost and high product yield, simultaneously. The obtained Cs2Na0.9Ag0.1In0.95Bi0.05Cl6 microcrystals exhibit bright self-trapped excitons emission with quantum yield of (98.3 ± 3.8)%, which could retain (90.5 ± 1.3)% and (96.8 ± 0.8)% after continuous heating or ultraviolet-irradiation for 1000 h, respectively. The phosphor converted-LED exhibited near-unity conversion efficiency from ultraviolet chip to self-trapped excitons emission at ~200 mA. Various ions doping (such as Cs2Na0.9Ag0.1InCl6:Ln3+) and other derived lead-free perovskite materials (such as Cs2ZrCl6 and Cs4MnBi2Cl12) with high luminous performance are all realized by our proposed strategy, which has shown excellent availability towards commercialization.
ABSTRACT
The nanocomposites of reduced graphene oxide (RGO) and polyoxometalates (POMs) have been considered to be effective to boost more Li+ to participate in intercalation/deintercalation process of lithium-ion batteries (LIBs). In this paper, a nanocomposite (PMo12@RGO-AIL) with electrostatic interaction of RGO and Keggin-type [PMo12O40]3- has been fabricated and characterized by XRD, XPS, SEM, and TEM. To prepare PMo12@RGO-AIL, a strategy of covalent modification is developed between amino-based ionic liquid and RGO, helping to achieve the uniform dispersion of [PMo12O40]3-. When the PMo12@RGO-AIL was used as a cathode for LIBs, it could exhibit more excellent reversible capacity, cycle stability, and rate capability than those of samples without modifying by ionic liquids. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11051-020-05108-x.
