Study On Near Infrared Colloidal Quantum Dots LEDs And Filters

Compared with traditional materials,near-infrared colloidal quantum dots?also known as semiconductor nanocrystals?have infrared fluorescence spectrum,wide absorption spectrum,narrow half-width and high fluorescence quantum yield.It shines in optical applications,bioluminescent labels,gas detection,and defense industry.At the same time,quantum confinement effects,surface effects,quantum tunneling,Coulomb blocking effects and dielectric confinement effects are also manifested in semiconductor nanocrystals.Based on blue GaN light-emitting diodes,near-infrared colloidal quantum dot phosphors are used for light conversion,and two types of near-infrared colloidal quantum dot sources are prepared.Near-infrared colloidal quantum dots and polyvinyl butyral?PVB?are uniform mixed and deposited on quartz glass in order to complete the fabrication of two types of near-infrared colloidal quantum dot filters.details as follows:1.Synthesis and characterization of near-infrared colloidal quantum dotsTwo kinds of quantum dots,PbSe and AgInSe₂/ZnS,were synthesized and their luminescence spectra,absorption spectra,XRD and TEM were characterized.2.Preparation and performance analysis of near-infrared colloidal quantum dot LEDBased on blue GaN light-emitting diodes,PbSe quantum dot phosphors were used for light conversion,and PbSe quantum dot light-emitting diodes were fabricated with EQE of 1.78%.Based on blue-light gallium nitride light-emitting diodes,AgInSe₂/ZnS quantum dot phosphors were used for light.Conversion,an AgInSe₂/ZnS quantum dot light emitting diode was prepared with EQE of 1.6%.3.Preparation of near-infrared colloidal quantum dot filtersand transmission analysisBased on the quartz glass as the substrate,PbSe quantum dots and polyvinyl butyral?PVB?were uniformly mixed and then deposited into a film to complete the preparation of PbSe quantum dot filters.The first exciton absorption peak at 1450nm filter:the cut-off interval is from visible light to 1450 nm,the minimum transmittance in the cut-off interval is about 14.2%,the transmission interval is from 1667 nm to near-infrared,and the highest transmittance in the transmission interval is about82.1%.The first exciton absorption peak at 1490 nm filter:the cut-off interval is from visible light to 1490 nm,the minimum transmittance in the cut-off interval is about13.1%,the transmission interval is from 1693 nm to near-infrared,and the highest transmittance in the transmission interval is about 81.5%.The first exciton absorption peak at 1590 nm filter:the cut-off interval is from visible light to 1590 nm,the minimum transmittance in the cut-off interval is about 11.9%,the transmission interval is from 1721 nm to near-infrared,and the highest transmittance in the transmission interval is about 82.7%.Based on quartz glass as the substrate,AgInSe₂/ZnS quantum dots and polyvinyl butyral?PVB?were uniformly mixed and then deposited into a film to complete the preparation of AgInSe_2/ZnS quantum dot filters.The luminescence peak at 747 nm filter:the cut-off interval is from 300 nm to 500 nm,the minimum transmittance in the cut-off interval is about 12.1%,the transmission interval is from 800 nm to 1100nm,and the highest transmittance in the transmission interval is about 78.3%.The luminescence peak at 1013 nm filter:the cut-off interval is from 300 nm to 600 nm,the minimum transmittance in the cutoff interval is about 12.3%,the transmission interval is 860 nm to 1100 nm,and the highest transmittance in the transmission interval is about 76.5%.The luminescence peak at 1136 nm filter:the cut-off interval is from 300 nm to 700 nm,the minimum transmittance in the cut-off interval is about12.5%,the transmission interval is from 925 nm to 1100 nm,and the highest transmittance in the transmission interval is about 74.3%.