Metallic nanostructures for efficient LED lighting

Abstract

Light-emitting diodes (LEDs) are driving a shift toward energy-efficient illumination. Nonetheless, modifying the emission intensities, colors and directionalities of LEDs in specific ways remains a challenge often tackled by incorporating secondary optical components. Metallic nanostructures supporting plasmonic resonances are an interesting alternative to this approach due to their strong light–matter interaction, which facilitates control over light emission without requiring external secondary optical components. This review discusses new methods that enhance the efficiencies of LEDs using nanostructured metals. This is an emerging field that incorporates physics, materials science, device technology and industry. First, we provide a general overview of state-of-the-art LED lighting, discussing the main characteristics required of both quantum wells and color converters to efficiently generate white light. Then, we discuss the main challenges in this field as well as the potential of metallic nanostructures to circumvent them. We review several of the most relevant demonstrations of LEDs in combination with metallic nanostructures, which have resulted in light-emitting devices with improved performance. We also highlight a few recent studies in applied plasmonics that, although exploratory and eminently fundamental, may lead to new solutions in illumination.

Organic Solid-State Tri-Wavelength Lasing from Holographic Polymer-Dispersed Liquid Crystal and a Distributed Feedback Laser with a Doped Laser Dye and a Semiconducting Polymer Film

“…For the diffraction order m > 1, the lasing radiation is coupled out of the waveguide by an angle α relative to the HPDLC DFB laser surface normal via grating coupling [27,28,29,30] as shown in Figure 1c. The guided mode travelling in the HPDLC DFB laser [28] can be expressed as $k^2={false(n{G}_0-k_0\sin \alpha false)}^2,$ where k is the wavenumber of the light travelling in the MEH-PPV film, n is an integer, G 0 is the wavenumber of the HPDLC grating ( G 0 = 2πΛ −1 ), and k 0 is the wavenumber of the light in vacuum.…”

Measuring Ultrafast Spectral Diffusion and Correlation Dynamics by Two‐Dimensional Electronic Spectroscopy

“…These materials, especially CdSe quantum dots (QDs), have found various applicationss uch as biological imaging, solid-state lightings and lasers. [56][57][58][59][60] In these applications, one key parameter to optimize is the ensemble emission linewidth. The homogeneity,i nhomogeneity ands pectral diffusion dynamics which contributes to this linewidth are therefore of interests to scientists.…”

Flexible and Adaptable Light‐Emitting Coatings for Arbitrary Metal Surfaces based on Optical Tamm Mode Coupling

“…[4][5][6][7][8] However, the necessary confinement of the active material in a small region close to the metallic resonator entails a restriction on the maximum radiance achievable. An alternative to employing metallic nanostructures is the use of hybrid metal-dielectric systems [9,10] where the electromagnetic field can be tailored in such a way that the emission of light sources can be enhanced while reducing absorption losses. Among the latter, an approach that allows controlling the luminescence of a source layer over large areas is based on the concept of Tamm-state-mediated photoemission.…”