Relaxation and Excitation Rate Modifications by Metal Nanostructures for Solar Energy Conversion Applications

Abstract

Metal nanostructures supporting plasmonic resonances offer pronounced modifications of an electromagnetic environment for efficient light harvesting in solar energy conversion applications. Since these modifications may give rise to competing effects, boosting overall conversion efficiency needs optimization of structural and spectral parameters of emitter-metal nanostructure hybrid systems. Here, we employ finite-difference time-domain simulations to investigate modifications in relaxation and excitation rates of a dipole emitter in proximity to three representative gold nanostructures, namely nanospheres, nanorods, and slot antennas. We present detailed investigations of parameter space in terms of nanostructure type, emitter position, and spectral range to identify regions of optimum performance for solar energy conversion applications. Our results suggest that for selected parameter sets, hybrid systems yield substantial enhancement in the excitation rate as well as suppression of luminescence, which are primary considerations in photovoltaic and photocatalysis applications, whereas regions of enhanced luminescence are more favorable for luminescent solar concentrators. Nanostructures with a higher aspect ratio are found to be more efficient. Particularly, the gap modes of slot antennas exhibit pronounced suppression of luminescence yield and light confinement over a broad spectral range from 550 nm up to 2200 nm, besides offering a larger usable volume compared to singular nanoparticles investigated here.

Raman spectroscopy of PPV in the proximity of metal nanogaps

“…These nanogap structures can be precisely fabricated using current techniques such as focused ion beam (FIB) milling, electron beam lithography, and Photolithography combined with atomic layer deposition (ALD). So far, the metal nanogaps structure has already been explored for various applications such as surface-enhanced Raman scattering (SERS) [9], [10], sensing [11], [12], and solar energy conversion [13]. These nanogap structures can be further explored to study the molecular light-matter interaction.…”

Purcell enhancement of a quantum emitter placed within the Nanoparticle on Mirror cavity

“…This strong electromagnetic (EM) field confinement is attributed to Localized surface plasmon resonance (LSPR) and is the key to various optical phenomena such as surface-enhanced Raman spectroscopy (SERS) [1][2], enhanced fluorescence [3][4], enhanced sensing [5] [6], nonlinear plasmonics [7] [8], etc. Apart from this, the plasmonic cavity made by these nanoparticles also greatly alters the dynamics of a quantum emitter [9]. As suggested by Purcell in 1946, when an emitter is placed in the proximity of a resonant cavity, the spontaneous emission (SE) decay rate of the emitter changes.…”

Anapole-assisted ultra-narrow-band lattice resonance in slotted silicon nanodisk arrays

“…Well-designed plasmonic nanoantennas have the ability to limit light to the deep-subwavelength range [1,2] and inspire strong field enhancement due to the localized surface plasmon resonance (LSPR) [3][4][5]. Due to their strong field enhancement characteristics, metallic plasmonic nanoantennas can be applied to a variety of nanophotonic fields, including surface-enhanced infrared absorption [6,7], surface-enhanced Raman scattering, plasmonic refractive index sensing, etc.…”