40 research outputs found
Simulations of solar cell absorption enhancement using resonant modes of a nanosphere array
We propose an approach for enhancing the absorption of thin-film amorphous silicon solar cells using periodic arrangements of resonant dielectric nanospheres deposited as a continuous film on top of a thin planar cell. We numerically demonstrate this enhancement using 3D full field finite difference time domain simulations and 3D finite element device physics simulations of a nanosphere array above a thin-film amorphous silicon solar cell structure featuring back reflector and anti-reflection coating. In addition, we use the full field finite difference time domain results as input to finite element device physics simulations to demonstrate that the enhanced absorption contributes to the current extracted from the device. We study the influence of a multi-sized array of spheres, compare spheres and domes and propose an analytical model based on the temporal coupled mode theory
Efficient Coupling between Dielectric-Loaded Plasmonic and Silicon Photonic Waveguides
The realization of practical on-chip plasmonic devices will require efficient coupling of light into and out of surface plasmon waveguides over short length scales. In this letter, we report on low insertion loss for polymer-on-gold dielectric-loaded plasmonic waveguides end-coupled to silicon-on-insulator waveguides with a coupling efficiency of 79 ± 2% per transition at telecommunication wavelengths. Propagation loss is determined independently of insertion loss by measuring the transmission through plasmonic waveguides of varying length, and we find a characteristic surface-plasmon propagation length of 51 ± 4 μm at a free-space wavelength of λ = 1550 nm. We also demonstrate efficient coupling to whispering-gallery modes in plasmonic ring resonators with an average bending-loss-limited quality factor of 180 ± 8
A Breakthrough Propulsion Architecture for Interstellar Precursor Missions: Phase I Final Report
Our breakthrough propulsion architecture is an innovative way to take advantage of kilometer-scale, multi-hundred megawatt, space-based, phased-array lasers to enable rapid transportation throughout the solar system. In this architecture, the laser would beam power over distances of up to 40 AU increasing the available power density relative to solar insolation by two orders of magnitude. The receiving vehicle would have a photovoltaic array with cells tuned to the laser frequency that outputs a voltage of 6 kV to directly-drive a lithium-fueled gridded ion thruster system at an ultra-high specific impulse of 40,000 s. Such a system could enable final spacecraft speeds of greater than 40 AU/year, potentially enabling missions to the solar gravity lens focus at 550 AU in less than 15 years. This is the propulsion architecture of the 22nd century
Efficient Coupling between Dielectric-Loaded Plasmonic and Silicon Photonic Waveguides
Solar cell efficiency enhancement via light trapping in printable resonant dielectric nanosphere arrays
Resonant dielectric structures are a promising platform for addressing the key challenge of light trapping in thin-film solar cells. We experimentally and theoretically demonstrate efficiency enhancements in solar cells from dielectric nanosphere arrays. Two distinct amorphous silicon photovoltaic architectures were improved using this versatile light-trapping platform. In one structure, the colloidal monolayer couples light into the absorber in the near-field acting as a photonic crystal light-trapping element. In the other, it acts in the far-field as a graded index antireflection coating to further improve a cell which already included a state-of-the-art random light-trapping texture to achieve a conversion efficiency over 11%. For the near-field flat cell architecture, we directly fabricated the colloidal monolayer on the device through Langmuir–Blodgett deposition in a scalable process that does not degrade the active material. In addition, we present a novel transfer printing method, which utilizes chemical crosslinking of an optically thin adhesion layer to tether sphere arrays to the device surface. The minimally invasive processing conditions of this transfer method enable the application to a wide range of solar cells and other optoelectronic devices.
False-color SEM image of an amorphous silicon solar cell with resonant spheres on top
Photon and carrier management design for nonplanar thin-film copper indium gallium selenide photovoltaics
Guide plasmonique polymère-métal : composants passifs et actifs pour la photonique intégrée
Dielectric loaded surface plasmon polariton waveguides (DLSPPWs) enable transmission at a sub-wavelength scale of both electrical and plasmonic (optical waves at the interface between a metal and a dielectric) signals in the same circuitry. Moreover, the use of a polymer as the dielectric load enables the functionalization of DLSPPWs. Therefore, this configuration is of great interest for integrated photonic applications. However, DLSPPWs suffer strong losses due to dissipation into the metal film. We address here the possibility of compensating the losses using a configuration analogous to an optical amplifier. We first set theoretical (effective index model), numerical (differential method and Green's function method) and experimental (leakage radiation microscopy) tools adapted for the optimization and the characterization of these guides. Once the modal confinement has been optimized at telecom wavelength λ=1.55 µm, we consider a polymer doped with quantum dots. The guided surface plasmon mode in the doped polymer-metal system is excited while an additional laser pumps the quantum dots in their excited states. Quantum dots relaxation by stimulated emission of surface plasmon polariton offers an optical gain. This phenomenon is characterized by leakage radiation microscopy in the direct space (imaging plane) and in the back focal space (Fourier plane). This demonstration is a step towards integrated photonics and interconnection of all-optical miniaturized circuitry.Les guides d'onde plasmoniques induits par un ruban diélectrique (DLSPPWs pour "Dielectric Loaded Surface Plasmon Polariton Waveguides") permettent de transmettre à une échelle sub-longueur d'onde, des signaux électriques et plasmoniques (ondes optiques à l'interface entre un métal et un diélectrique) dans la même circuiterie. De plus, l'utilisation d'un ruban de polymère comme diélectrique permet de fonctionnaliser ces DLSPPWs. Cette configuration est par conséquent d'un grand intérêt pour des applications en photonique intégrée. Néanmoins, les DLSPPWs souffrent de pertes importantes en raison de la dissipation dans le métal. Nous abordons le problème en montrant qu'il est possible de compenser les pertes en utilisant une configuration analogue à celle d'un amplificateur optique. Nous mettons d'abord en place les outils théoriques (modèle de l'indice effectif), numériques (méthode différentielle et méthode de la fonction de Green) et expérimentaux (microscopie à fuites radiatives) adaptés à l'optimisation et la caractérisation des DLSPPWs. Une fois le confinement modal maximisé à la longueur d'onde telecom λ=1.55 µm, nous considérons un polymère dopé avec des boîtes quantiques. Le mode plasmon guidé dans le système polymère dopé-métal est excité pendant qu'un laser pompe les boîtes quantiques dans leur état excité. La relaxation des boîtes quantiques par émission stimulée de plasmon-polariton de surface apporte un gain optique. Ce phénomène est caractérisé par microscopie à fuites radiatives dans l'espace direct et dans l'espace réciproque. Cette démonstration représente un élément clé pour la photonique intégrée et l'interconnexion de circuits tout-optiques miniaturisés
Guide plasmonique polymère-métal (composants passifs et actifs pour la photonique intégrée)
Les guides d onde plasmoniques induits par un ruban diélectrique (DLSPPWs pour "Dielectric Loaded Surface Plasmon Polariton Waveguides") permettent de transmettre à une échelle sub-longueur d onde, des signaux électriques et plasmoniques (ondes optiques à l interface entre un métal et un diélectrique) dans la même circuiterie. De plus, l utilisation d un ruban de polymère comme diélectrique permet de fonctionnaliser ces DLSPPWs. Cette configuration est par conséquent d un grand intérêt pour des applications en photonique intégrée. Néanmoins, les DLSPPWs souffrent de pertes importantes en raison de la dissipation dans le métal. Nous abordons le problème en montrant qu il est possible de compenser les pertes en utilisant une configuration analogue à celle d un amplificateur optique. Nous mettons d abord en place les outils théoriques (modèle de l indice effectif), numériques (méthode différentielle et méthode de la fonction de Green) et expérimentaux (microscopie à fuites radiatives) adaptés à l optimisation et la caractérisation des DLSPPWs. Une fois le confinement modal maximisé à la longueur d onde telecom ?=1.55 m, nous considérons un polymère dopé avec des boîtes quantiques. Le mode plasmon guidé dans le système polymère dopé-métal est excité pendant qu un laser pompe les boîtes quantiques dans leur état excité. La relaxation des boîtes quantiques par émission stimulée de plasmon-polariton de surface apporte un gain optique. Ce phénomène est caractérisé par microscopie à fuites radiatives dans l espace direct et dans l espace réciproque. Cette démonstration représente un élément clé pour la photonique intégrée et l interconnexion de circuits tout-optiques miniaturisés.Dielectric loaded surface plasmon polariton waveguides (DLSPPWs) enable transmission at a sub-wavelength scale of both electrical and plasmonic (optical waves at the interface between a metal and a dielectric) signals in the same circuitry. Moreover, the use of a polymer as the dielectric load enables the functionalization of DLSPPWs. Therefore, this configuration is of great interest for integrated photonic applications. However, DLSPPWs suffer strong losses due to dissipation into the metal film. We address here the possibility of compensating the losses using a configuration analogous to an optical amplifier. We first set theoretical (effective index model), numerical (differential method and Green s function method) and experimental (leakage radiation microscopy) tools adapted for the optimization and the characterization of these guides. Once the modal confinement has been optimized at telecom wavelength ?=1.55 m, we consider a polymer doped with quantum dots. The guided surface plasmon mode in the doped polymer-metal system is excited while an additional laser pumps the quantum dots in their excited states. Quantum dots relaxation by stimulated emission of surface plasmon polariton offers an optical gain. This phenomenon is characterized by leakage radiation microscopy in the direct space (imaging plane) and in the back focal space (Fourier plane). This demonstration is a step towards integrated photonics and interconnection of all-optical miniaturized circuitry.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF
Broadband light output enhancement for scintillator using whispering‐gallery modes in nanospheres
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108062/1/pssa201431032.pd