Research Of Out-coupling Efficiency Enhancement Of The OLED Basement With Microstructure

Organic Light-emitting Diodes(OLEDs) have great prospects in its display and lighting field,because of the good advantages such as self-luminous, wide material selection range, fast response,light weight, high visibility, high brightness, high-speed with not flicker imaging, high contrast,wide viewing angle,etc., the country has many companies began to study OLED until 2015.However, its low out-coupling efficiency hinders its rapid development.There are three methods to improve the out-coupling efficiency of the OLED:.decreasing in waveguide effect, reducing non-light emitting mode, reducing total internal reflection. This article adopts the method of attached microstructure on the glass substrate, broke light rays occurred total internal reflection on the glass and air interface, to make more light rays escape, reduce the total internal reflection, and will not affect the radiation spectral distribution.The main work is as follows:Firstly,Introduction of the prospects for the development of the OLED, the structure and light-emitting principle, the review about the research status about improve the OLED light efficiency with micro-structure.Secondly, analyzed in detail the principle of the angle of slope of the pyramidal structure to enhance the out-coupling efficiency of OLED substrate, design three pyramidal structure(three pyramid structure, the structure of the cone, rectangular pyramid structure), followed by simulation the angle of slope,refractive index, spacing, bottom diameter and other parameters how to influence on improving the out-coupling efficiency of OLED substrate, design the structure parameter is the most effective for improving the out-coupling efficiency.Then, analyzed in detail the principle of the microlens array to improve light extraction efficiency of the OLED substrate, designed and optimized structural parameters of spherical microlens and aspherical microlens array with TracePro software, design the structure parameter is the most effective for improving the out-coupling efficiency.Lastly,Produced a variety of microlens array template used digital grayscale mask technology. Produced PDMS film of microlens array approach by copying, microlens array film with adhesive stickers to the OLED substrate surface, tested to improve the out-coupling efficiency optical efficiency。Test results showed that: the substrate is hexagonal parabolic microlens array film, the spacing is zero, the vector height- diameter ratio equal to 0.6, can most effectively improve the out-coupling efficiency, the test results are consistent with the theory of the law, but the measured value is lower than the theoretical value. It analyzes the reasons resulting in low test results.