Microlens Array Based On Soft Lithography Technology For Production

Organic light emitting diodes (OLEDs) have attracted much attention for several applications, such as light source and display. It is of both commercial and scientific interests to improve external quantum efficiency of such light emitters. The external quantum efficiency of OLED is determined by the combination of charge balance, singlet-triplet ratio and light extraction efficiency. The paper focuses on the air/substrate interface to enhance the external quantum efficiency of organic light-emitting devices. It is reported that a method enhances the external quantum efficiency of organic light-emitting devices, employing microlens arrays based on the soft-lithography.Chapter one introduces the advantage, structures, and mechanism of the organic light-emitting diode, as well as evaluation of its main parameters. OLED is a promising display technology. In chapter two, introduction to the refractive and diffractive microlens is put forward, especially to the fabrication sequence of refractive ones, and the techniques for pattern transfer. In chapter three, a theoretical model based on Tracepro is developed to simulate the effects and optimize the structure parameters of the microlens array. The structure parameters of the microlens array are important for the refractive microlens arrays to enhance the external quantum efficiency of organic light-emitting devices. In chapter four, fabrication techniques of refractive microlens of OLED is studied, which shows good results by first making cylinder type microlens on the glass substrate, then shortening the size of microlens with the help of photoresist. With the use of microlens arrays, the light extraction factor is increased experimentally.