The influence of a microlens array on planar organic light-emitting devices

Abstract

Though microlens arrays have been used to enhance luminance efficiency and luminance power efficiency of light-emitting diodes (LEDs) and organic LEDs, the influence of the parameters of a microlens array on the efficiency improvement has not been systematically discussed. In this study, the influences of the edge length and the gap of the microlens array on the luminance efficiency, CIE index and optical emitting spectrum of planar OLED devices will be explored. Additionally, a method of analyzing the performance of the luminance efficiency improvement of the device per single microlens in a microlens array of known microlens number density is to be demonstrated.

Development and characterization of adjustable refractive index scattering epoxy acrylate polymer layers

“…3,4 Another possibility to increase the light out coupling is lenses on the surface of OLEDs. [5][6][7][8][9][10][11][12] Hollow spheres embedded in the layers 13 or glass substrates blast with sand 14 are other possibilities for scattering the light. However, these methods are very time-consuming or very costly.…”

Nanophosphor Coatings: Technology and Applications, Opportunities and Challenges

“…n[GaN] = 2.5). However, even for organic LEDs (OLEDs) which employ materials with moderate values of refractive index (n~1.5), only about 20-30% of light would escape into air (Wei et al, 2006). Refractive indices of dielectrics used as phosphor hosts fall into the range between 1.5 and 2.5 and, therefore, the brightness of any single-crystalline phosphor screen should also be strongly affected by the internal reflection.…”

Rapid laser fabrication of microlens array using colorless liquid photopolymer for AMOLED devices

“…Microlens array (MLA) technologies not only as a passive optical element but as an active optical element with dynamically tunable focal length, have been widely studied and developed for the purpose of being applied to lithography [1], 3D imaging systems [2], image sensors [3] and optical communications [4], as well as to OLED devices [5][6][7][8][9]. Two kinds of tunable fluids are used for dynamically controlling the focal length, one is using the liquid crystal (LC)-based microlens array [10] and the other is using the electro wetting-based microlens array [11].…”