Fabrication Of Composite Film Mlas On Flexible Substrate And Research Of It's Application On OLED

Organic Light Emitting Device(OLED)has developed very rapidly in recent years.Its advantages include wide viewing angle,high contrast,low energy consumption,long life,and flexible display.After LCD display can not meet current needs,it is considered as a new generation of lighting and display devices.However,due to the existence of the difference in refractive index between the OLED device substrate and the air medium,photons will be reflected and refracted,causing most of the photons can not escape into the air,and the light extraction efficiency is low,which greatly restricts the development and application of OLED.In recent years,scientific researchers have improved the light extraction efficiency of OLED devices by combining microlens arrays with OLED devices.In this paper,microlens array structures of different shapes and sizes were prepared on organic-inorganic composite films by nano-imprinting method,and then applied to green OLED devices to discuss the effect of microlens array structure on the light-emitting performance of OLED devices.The specific research content is as follows:By combining the sol-gel method and the spin coating method,the PMMA-doped and ultraviolet-sensitive titanium dioxide-based organic-inorganic composite film is prepared on a flexible substrate.The optical transmittance of the composite film with a PMMA content of 0-10 wt.% are tested.The results showed that when the PMMA content increased,the optical transmittance of the composite film is increased.When the PMMA content was 10 wt.%,the transmittance of the visible area can reach about 86%.The surface roughness of composite films with PMMA content of 0-10 wt.% was tested too,the results showed that the surface roughness of composite films with different PMMA content were all lower than 0.5 nm.The photochemical structure properties of the composite film were studied by Fourier infrared absorption spectroscopy.The circular and hexagonal microlens array structures are respectively prepared on the composite film by the nanoimprint method.The surface morphology of the composite film microlens array structure was observed through an optical microscope and a scanning electron microscope.The result showed that the prepared composite film microlens array had a clear outline,a complete structure and a smooth surface.The surface profile of the composite film microlens array structure was tested by a surface profiler,and the diameter range of the microlens was 39-62 ?m.The focusing and imaging performance of the composite film microlens array structure was studied,and the results showed that the prepared composite film microlens array structure had excellent optical focusing and imaging performance.Finally,a OLED device is prepared on the back of the composite film microlens array structure by a deposition method.The effects of different microlens shapes and sizes as well as the PMMA content in the composite thin-film microlens array on the luminescence performance of OLED devices are studied.The results show that the small-size hexagonal microlens array structure has a relatively high improvement in the luminance and current efficiency of the OLED device.In addition,increasing the PMMA content in the composite film microlens array structure is also conducive to improving the light-emitting performance of the OLED device.