Nano-structured metallic electrodes for plasmonic optimized light-emitting diodes

Abstract

Metallic nanostructures have attracted large interest recently due to new optical properties caused by plasmonic effects. The exceptionally high transmission of light through periodically structured metals is originated by interactions between light and plasmonic resonances. These resonances are controllable by varying periodicity and geometrical dimensions of the metal gratings. Our aim is the utilization of these effects to improve the efficiency of conventional light-emitting diodes (LED). The application of one-dimensional periodic metallic gratings as top electrodes of LEDs offers advantages such as efficient and homogeneous current injection, enhanced light output, modified angular light emission characteristics and linear polarization of the emission. Based on finite-difference time-domain simulations, we optimized the parameters for gold and silver gratings on top of InGaAs/GaAs/AlAs heterostructures. Fabrication of these structures was carried out using laser interference lithography (LIL) and a lift-off process. We measured the optical transmission of these structures and were able to demonstrate a polarization-and wavelength-dependence in good consistency with our calculations.

Gold nanonetwork film on the ITO surface exhibiting one-dimensional optical properties

“…600 to 800 nm, respectively. This enables them to produce peculiar optical properties for use in a broad range of applications including nanophotonics [ 6 - 11 ], light-emitting diode [ 12 ], photovoltaics [ 13 - 17 ] and photosynthesis efficiency enhancement [ 18 , 19 ] and optical sensing applications [ 20 ]. For example, nanorods demonstrate a unique profile and enhanced energy of electron-wave scattering upon exposure to the electromagnetic irradiation resulting from their anisotropic localised-plasmonic excitation character [ 21 , 22 ], placing them as a potential agent for photodynamic therapy of cancer cells [ 19 , 23 - 26 ], optical contrast agent and for diagnostic imaging applications [ 20 , 27 , 28 ].…”

Inexpensive and fast wafer-scale fabrication of nanohole arrays in thin gold films for plasmonics

“…Hole arrays in thin metal films are interesting for a number of applications related to plasmonics. For example, they can be used as surface plasmon resonance (SPR) sensors, transparent electrodes for light-emitting diodes (LED), to enhance the efficiency of solar cells, or act as optical filters [1][2][3][4][5][6][7][8]. Previous methods for the large-scale fabrication of nanoscale hole arrays have been shown.…”