Controllable antimony-doped high-luminous-efficiency blue-light perovskite nanosheet and preparation method thereof

Abstract

The invention relates to a controllable antimony-doped blue light perovskite nanosheet with high photosynthetic efficiency and a preparation method thereof, lead salt, cesium salt and antimony salt are used as raw materials, organic acid and organic ammonium are used as ligands, dimethylformamide or dimethyl sulfoxide is used as a solvent, and the antimony-doped blue light perovskite nanosheet CsPbClyBr3-y: xSb is synthesized in situ in a toluene solution by using a ligand-assisted method. By introducing antimony doping, the n-layer perovskite nanosheet can be formed, the fluorescence quantum yield (PLQY) can be improved, the fluorescence lifetime can be shortened, for single bromine halogen perovskite nanocrystals, blue shift of the fluorescence peak can be achieved, the blue light emission peak ranges from 456 nm to 470 nm, and for the antimony-doped bromine lead perovskite nanosheet at the 465 nm light emission peak, the blue light emission peak ranges from 45 nm to 470 nm. The fluorescent quantum yield is up to 95%, the half-wave width is only 19 nm, and the fluorescent lifetime is very short as 1.48 ns.

Description

technical field [0001] The invention belongs to the technical field of photoelectric material preparation, and relates to a controllable antimony-doped high light-efficiency blue light perovskite nanosheet and a preparation method thereof. Background technique [0002] In recent years, semiconductor quantum dots have attracted much attention in the fields of optoelectronics and display. Among them, all-inorganic lead halide perovskite quantum dots (CsPbX 3 ; where X=Cl, Br or I) has become a new technology due to its advantages such as simple synthesis and preparation process, high fluorescence efficiency, extremely narrow luminescence half-peak width, tunable band gap, low defect density and wide color gamut coverage. A generation of highly competitive luminescent materials with potential applications in solar cells, light-emitting diodes, lasers and other fields. [0003] At present, most researches focus on perovskite quantum dots with cube-like morphologies around 10 n...

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Problems solved by technology

[0005] However, although insulating long organic ligands can effectively stabilize nanosheets and achieve high fluorescence quantum yield (PLQY value), too much long ligands will severely inhibit charge injection and transfer, which is detrimental to device performance.

In addition, due to the high dynamic nature of the ligands on the perovskite surface, the binding force between the surface ligands and the nanosheets is weak, and these organic ligands are easily detached and desorbed from the surface of the nanosheets.

Not only the structural integrity of nanosheets will deteriorate during the purification process, but also the enrichment of nanosheets during film formation can easily cause aggregation and precipitation, resulting in red-shifted emission peaks, so it is difficult to obtain dense nanosheet film

[0006] In the blue light band, the quantum efficiency of quantum dots obtained simply by adjusting Cl and Br halogens is usually low (below 30%), and their stability is poor, which limits their potential in industrial applications.

[0007] At present, it has been reported that the generation of CsPbCl can be regulated by changing the carbon chain length of the ligand or the ratio of the ligand, controlling the synthesis temperature, etc. x Br 3-x nanosheets, but often requires complex and tedious steps to obtain uniformly sized nanosheets

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