微透镜阵列薄膜定向增强OLED耦合效率的研究

Directional out-coupling efficiency enhancement of OLED with microlens array films

利用微透镜阵列(MLA)薄膜定向增强有机发光器件(OLED)耦合效率,采用光线追迹方法模拟了不同长短轴比的椭圆形MLA对OLED光的定向增强作用。采用数字微反射镜器件(DMD)并行光刻和热回流相结合的方法制作了MLA模版,经过电铸、压印得到MLA薄膜。理论模拟和实验结果表明,利用MLA可以定向提高OLED的出光效率,圆形MLA可提高垂直OLED基底表面方向的亮度42%;椭圆形MLA可实现OLED在长短轴方向上30°的半强度角度差,总的提取效率可提高30%以上。

The directional out-coupling efficiency enhancement of an organic light-emitting device（OLED） is discussed,which can be realized by using microlens array（MLA） film attached to OLED.The ray tracing method is used to simulate the directional enhancement effects of the out-coupling efficiency by elliptical MLA with different major-minor axis ratios.The microlens array mold is fabricated by digital micro-mirror device（DMD） based parallel photolithography and the thermal reflow method.The MLA film is finally obtained by using electroplating and imprinting techniques.Both simulation and experimental results show that the directional out-coupling efficiency of OLED can be improved with MLA film.The luminance in normal direction of OLED attached with a spherical microlens array film is improved by 42%,and the half-intensity angle difference between the major axis and the minor axis is up to 30° by attaching an elliptical microlens array film.The total out-coupling efficiency of an OLED attached with MLA film is increased over 30%.