Doubling Coupling-Out Efficiency in Organic Light-Emitting Devices Using a Thin Silica Aerogel Layer

Abstract

An innovative way of enhancing the coupling‐out efficiency in light‐emitting diodes (LEDs) is revealed. A very low‐refractive‐index silica aerogel is placed between the substrate and the emissive layer to obtain a perfect decoupling of the propagation modes within the emissive layer from the glass substrate. The Figure shows an ultrathin emissive layer on a glass substrate with (left) and without (right) an aerogel spacer layer under UV irradiation (see also cover).

Spectrally narrowed leaky waveguide edge emission and transient electrluminescent dynamics of OLEDs

“…Substrate surface modification 68,69 can extract the glass mode light; whereas, wave guided light out coupling methods include the use of sub-wavelength photonic crystals, 70 surface plasmons, 71 periodic dielectric mirrors, 72 very low index Aerogel layer, 73 and so on.…”

Transparent Aerogels with High Mechanical Strength Composed of Cellulose-silica Cross-linked networks

“…Aerogels which are characterized by large internal surface area and large open pores, are promising candidates for various advanced applications such as thermal insulation, catalysts/catalyst supports, acoustics, and gas filters [7][8][9][10][11][12][13][14][15].…”

Simulation Study on the Effect of the Emitter Orientation and Photonic Crystals on the Outcoupling Efficiency of Organic Light-Emitting Diodes

“…For example, the glass mode can be extracted from the substrate by forming either a microlens array or a diffusing layer on the glass substrate [5][6][7][8][9][10][11][12]. The internal bulk or interface structures were modified to extract the light trapped in the organic layers by, for example, reflector modification, insertion of low-index grids in the organic layers, interface or structure modification of the organic and ITO layers, and patterning the ITO electrodes along with an insertion of a high-conductivity polymer layer [13][14][15][16][17][18][19][20]. Hybrid structures may be used to extract both the trapped light in the waveguide mode and the glass mode [21,22].…”