| The free electrons in noble metal nanoparticles vibrate regularly with the external electromagnetic field,which is called plasma element.However,when noble metal nanoparticles have complex surface morphology,the collective vibration mode of free electrons becomes more complex,which leads to unique photoelectric characteristics such as high scattering cross section,multiple plasmon modes,and significantly enhanced near-field electromagnetic field intensity,which has attracted extensive attention and research interest.At present,the application of noble metal nanoparticles with complex surface morphology in biomolecular sensing,surface-enhanced Raman detection,photothermal conversion and other fields has been widely reported,but the application of noble metal nanoparticles in light-emitting devices is rarely studied.Meanwhile,as a new generation of light-emitting devices,organic light-emitting diode(OLED)has been widely used in lighting and display due to its advantages of low power consumption,high contrast and flexibility,and has wide application prospects.However,due to the limitation of device structure and material,the internal quantum efficiency of traditional OLED devices is close to 100%,while the external quantum efficiency of OLED devices is usually only about 20%.That is,most of the generated photons are trapped in the device and eventually lost as heat.Therefore,improving the external quantum efficiency of OLED devices,that is,emitting as many photons as possible into the external space,is particularly important for improving the luminous intensity and luminous efficiency of OLED devices and reducing the thermal loss of OLED devices.Therefore,the main contents of this paper are as follows.1.Sea urchin-like gold nanoparticles were selected as the representative noble metal nanoparticles with complex surface morphology,and sea urchin-like gold nanoparticles with different sizes and surface morphology were prepared by solution method.The effects of reactant concentration,reaction time and reaction conditions on the size and morphology of sea urchin-like gold nanoparticles were studied.High quality sea urchin-like gold nanoparticles with diameters of 70 nm,170 nm and 450 nm were rapidly prepared by an optimized preparation method.2.Using the Finite difference Time Domain(FDTD)method,a universal electromagnetic simulation model of sea urchin-like gold nanoparticles was established,and the electromagnetic response of sea urchin-like gold nanoparticles with different sizes and surface morphology was simulated at different frequencies.The results show that compared with other nanoparticles,70 nm sea urchin-like gold nanoparticles have better enhancement effect on short-wavelength visible light in both near and far field regions.3.White OLEDs device based on polymer-silver nanowires was prepared.The undoped white OLEDs has a starting voltage of 2.4V,a maximum brightness of 13000cd/m2,A maximum power efficiency of 55 lm/W,and a maximum current efficiency of59 cd/A.4.Based on the electromagnetic simulation results of sea urchin-like gold nanoparticles,70 nm sea urchin-like gold nanoparticles were doped into the flexible substrate,and highly efficient flexible white OLEDs were prepared based on the doped substrate.The results show that,compared with the undoped flexible OLED with the same structure and the OLED based on glass-ITO substrate,the OLED doped with 70 nm sea urn-like gold nanoparticles has a maximum power efficiency of 95.5 lm/W and a maximum current efficiency of 139 cd/A,with a starting voltage of 2.4 V,a maximum power efficiency of 95.5 lm/W and a maximum current efficiency of 139 cd/A.It is 1.73times and 1.49 times of the basic device.Its highest brightness is 37478 cd/m~2,which is2.88 times higher than that of the basic device.At the brightness of 10000 cd/m~2,the power efficiency and current efficiency of OLED doped with 70 nm sea urchin like gold nanoparticles are 56 lm/W and 126 cd/A,which are 4.1 times and 2.73 times higher than those of basic devices,respectively. |
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