| In recent years,the perovskite material has attracted more and more attention for which is one of the most competitive materials in the field of photovoltaic.Since 2009,the energy conversion efficiency of perovskite photovoltaic devices has exceeded 22.1%,which defeated the polysilicon solar cell and makes it becoming the star material.The perovskite materials have been wildly used in optical detector,optical waveguide,laser,LED and other optoelectronic devices due to its excellent properties including high fluorescence quantum efficiency,unique carrier separation properties,high charge carrier mobility and long effective diffusion lengths.The perovskite is nearly becoming an all-powerful material.Compared with the organic and inorganic perovskite,the all inorganic cesium lead halide perovskite CsPbX3(X = Cl,Br,I)is more stable.For nanomaterials,the size and morphology could affect their physical and chemical properties.So based on the current research,we focus on the synthetic method for acquiring different size and dimension of perovskite nanocrystals(quantum dots).Go a step further,we make full use of chemical and physical properties of perovskite quantum dots to explorer the new application of it,including the probe for metal ions,blind ultraviolet detector and optoelectronic photodetector.Specific innovations are as follows:1)Nowadays,the probing strategies for trace metal ions under various conditions is a hot area of research.For example,Cu2+ is nutritionally essential and medically important for a healthy life,but an excessive intake or high exposure can be toxic and harmful.In this paper,the CsPbX3 QDs are shown to perform as a new probe for metal ions with high sensitivity(<2nM),high selectivity,instant response and wide probing window ranging from 2×10-9 to 2×10-6.We explained the principle from both experimental and calculation.Also,the QDs are successfully applied for fast probing Cu2+ ions in edible oils and vehicle lubricating oils with the precision consistent to the values measured by inductively coupled plasma(ICP),which proves its usefulness.2)The solar-blind ultraviolet detection has the important strategic significance for it can be used in the area of space alert,missile identification tracking,the maritime detection and so on.For the first time,the perovskite quantum dot and Si nanowire radial pin hybrid solar blind photo-detector is proposed.We take advantage of excellent UV photoelectric absorption and high quantum efficiency of CsPbX3 QDs to down-convert the ultraviolet incidences into targeted absorption bands suitable for Si-based light absorption and sensing.What's more,compared to 300 nm in planar junction,the thin intrinsic layer thickness of radial junction cell is only 80 nm,which effectively shorten the detection time.The detector has the following advantages:(1)high responsivity of 54 mA W-1@200 nm,(2)fast rise/fall response time scales of 0.48/1.03 ms,(3)good stability,(4)low cost,can be fabricated over large area.3)Low dimensional semiconductor nanomaterials have shown their excellent properties for a large number of promising applications in decades.Here we report a strategy to synthesize all inorganic CsPbX3(X=Cl,Br,I)perovskite two-dimensional(2D)nanoplates by introducing additional metal halides MX'2 or MX'3(M=Cu,Zn,Al or Pb,etc.;X'=Cl,Br or I).These CsPbX3 perovskite nanoplates have uniform thickness and tunable size,which can be feasibly controlled by the component and ratio of the metal halides,temperature,time and ligands.The well defined morphology of the nanoplates makes them ideal building blocks for self-assembly in the face-to-face lineup arrangement.Compared to the optically isotropic CsPbX3 nanocubes,the 2D CsPbX3 nanoplates exhibit remarkable polarized UV-vis absorption and photoluminescence(PL)not only in liquid solvent and solid resin matrix,but also in self-assembled films.An optoelectronic photodetector sensitive for linear polarized light is fabricated to demonstrate the proof-of-concept. |
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