Preparation Of Infrared Quantum Dots-Composite Film And Reasearch On Optical Properties

In recent years,because of the infrared quantum dots' tunable emission wavelength,high fluorescence efficiency,simple preparation and solution of the advantages of workability,infrared quantum dots show good potential application in the field of infrared luminescence,such as light-emitting diode using infrared quantum dots can be used for night detection,medical diagnostics and environmental monitoring,and solar cells using infrared quantum dots can use unlight infrared parts more efficiently,etc.However,the stability of the infrared quantum dots need to be improved.For example,its relatively large specific surface area makes the surface of infrared quantum dots unstable,and its thermal and optical resistance as well as water and oxygen resistance are poor.Therefore,the direct application of infrared quantum dots is often impossible.If the infrared quantum dots are effectively compound,its stability can be improves,so that the infrared quantum dots composite material can be put into direct use,and its advantages can be truly exerted.In this paper,a series of reaserches on the synthesis of Pb S quantum dots and the preparation and optimization of Pb S quantum dots composite materials are carried out.The specific work is following:First,we synthetic surface ligands for oleic acid of Pb S quantum dots,and put them with polymers include polystyrene,polyvinylidene fluoride and polymethylmethacrylate respectively direct mixture preparation of composite films.But the films appear crack,decorative pattern and quantum dots scattered unevenly and bad phenomena such as reunion.It shows the compatibility between OA-Pb S quantum dots and thr polymer is poor.In order to improve the compatibility between Pb S quantum dots and polymer,this paper proposes a scheme of surface regulation of Pb S quantum dots: use Mono-2-(Methacryloyloxy)ethyl succinate ligands to replace the oleic acid ligands on the surface of Pb S quantum dots.Then,MMES-Pb S quantum dots are characterized.And the composite films are prepared by curing the MMES-Pb S quantum dots and the polymer epoxy resin adhesive thermally.The surface of the films is smooth without cracks and the quantum dots are evenly dispersed.When stored in the air for about 3 months,the absorption peak and photoluminescence peak of the film are only blue shifted about 30 nm,showing good spectral stability,but its photoluminescence quantum yield is low.In order to solve the problem of low photoluminescence quantum yield of the composite films,FDTD Solutions software is used to simulate the influence of different optical film structures on the light emission efficiency of its surface and edge,so as to explore the optical film structures with higher light efficiency in theory,and provide effective reference for the preparation of quantum dots optical films with high photoluminescence quantum yield.