Enhanced light out-coupling of organic light-emitting devices using embedded low-index grids

Efficient and bright organic light-emitting diodes on single-layer graphene electrodes

“…T he performance of organic light-emitting diodes has improved remarkably [1][2][3][4][5][6][7][8][9][10] in the last three decades. They are increasingly used in high-performance commercial displays owing to their many advantageous characteristics, which include vibrant colours, high contrast ratio, fast response time, thin and lightweight form factor, high energy efficiency and mechanical flexibility [5][6][7] .…”

“…They are increasingly used in high-performance commercial displays owing to their many advantageous characteristics, which include vibrant colours, high contrast ratio, fast response time, thin and lightweight form factor, high energy efficiency and mechanical flexibility [5][6][7] . In addition to display applications, Organic light-emitting diode (OLED) lighting is emerging as a competitive low-cost solid state lighting solution due to its high performance and attractive properties, such as thin and large area form factor, broad colour spectrum, gentle and diffused light output, colour tunability, transparency and flexibility [8][9][10] .…”

“…To date, tin-doped indium oxide (ITO) is the material of choice for TCE in OLEDs [1][2][3][4][5][6][7][8][9][10] owing to its exceptional optical and electrical properties. However, it has considerable shortcomings that potentially limit the further development of OLED technology.…”

Highly efficient inverted polymer light-emitting diodes using surface modifications of ZnO layer

“…One method of enhancing the out-coupling efficiency is to use a high-refractiveindex glass substrate and a hemisphere microlens thereon [16][17][18] . Moreover, a Bragg diffraction grating (BDG), a low-index grid and an internal scattering structure of the organic layer have been introduced in these devices for the light extraction of the indium tin oxide (ITO)/organic WG mode [19][20][21][22][23][24] . However, BDGs fabricated using the electron-beam lithography 19 , nanoimprinting 20 and holographic methods [21][22][23] incur the high costs and require complex techniques.…”

Surface plasmon-enhanced electroluminescence in organic light-emitting diodes incorporating Au nanoparticles

“…[4][5][6] However, the poor light extraction efficiency of $20% in a conventional OLED limits the external quantum efficiency due to the total internal reflection (TIR) at the glass substrate/air and indium-tinoxide (ITO)/substrate interfaces, the waveguide (WG) mode at the organic/ITO anode interface, and the surface plasmon (SP) losses at the metallic cathode/organic interface. [7][8][9][10] Various methods have been proposed to enhance light out-coupling in OLEDs, including surface microstructures on ITO anode to reduce the WG mode loss, 11,12 photonic crystals or microlens arrays attached on the glass substrate for the reduction of TIR, 13,14 corrugated cathode to reduce SP losses, [15][16][17][18] optical microcavity structures, 19 and so on. Recently, the localized SP effect excited by metallic nanostructures is becoming one of the most attractive approaches for light emission enhancement in OLEDs through the coupling with localized SP resonance and the emission energy.…”