Predicting Multi-Order Magnetic Polaritons Resonance in SiC Slit Arrays by Mutual Inductor–Inductor–Capacitor Circuit Model

Magnetic polariton (MP) that couples electromagnetic waves with magnetic excitation can be predicted by equivalent inductor–capacitor (LC) circuit model. However, when the resonance frequencies of MP and surface phonon polariton (SPhP) is close, the absorption and transmission peaks predicted by LC circuit model are far different from solving electromagnetic field calculation results. In this work, absorption and transmission enhancements with a SiC slit array are theoretically demonstrated within the SiC phonon absorption band with finite difference time-domain (FDTD) method. The interactions between SPhP and MP are confirmed by electromagnetic field distributions. Mutual inductor–inductor–capacitor (MLC) circuit model is used to predict the multiorder MP resonance conditions, and the coupling between MP and SPhP is treated as a mutual inductor in MLC model. The geometric effects of SiC slit arrays are investigated and MLC circuit model works well. This study may contribute to the design and prediction of thermal radiative properties and micro-/nanostructure metamaterials thermal radiative properties database building.

c-Si PV cells emissivity characterization at low operating temperatures for efficiency management

Efficiency is a critical parameter for a solar cell to be successful and is closely related to the working temperature of the cell. In turn, the temperature can be related to the infrared emissivity, the parameter that governs the thermal radiative properties of a body. In particular, the importance of infrared emissivity in a solar cell is essential in passive cooling applications, where controlled radiative thermal losses could let the cell operate at lower temperatures, the range where they present higher efficiency. In this presentation, the emissivity of c-Si solar cells in the low temperature range (around 50 ºC) is discussed. Traditionally, it has been determined by indirect reflectivity measurements at ambient temperature and extrapolated to working temperatures, but here, a direct measurement is proposed. For an accurate value the measurements are performed in the high accuracy radiometer of the University of the Basque Country, which allows spectral directional emissivity measurements as a function of temperature.

Accelerating the Discovery of Multilayer Nanostructures with Analytic Differentiation of the Transfer Matrix Equations

<div>Multilayer nanostructures represent an important class of materials with tunable optical and thermal radiative properties that can be leveraged for a wide range of energy applications. We present a theoretical framework for optimizing the geometry of such structures that utilizes gradients of various objective functions that are enabled through analytic differentiation of the transfer matrix equations. We demonstrate the usefulness of this method by applying it to the optimization of structures for incandescent light sources, and the global optimization of anti-reflective solar cell coatings.</div>

Accelerating the Discovery of Multilayer Nanostructures with Analytic Differentiation of the Transfer Matrix Equations

<div>Multilayer nanostructures represent an important class of materials with tunable optical and thermal radiative properties that can be leveraged for a wide range of energy applications. We present a theoretical framework for optimizing the geometry of such structures that utilizes gradients of various objective functions that are enabled through analytic differentiation of the transfer matrix equations. We demonstrate the usefulness of this method by applying it to the optimization of structures for incandescent light sources, and the global optimization of anti-reflective solar cell coatings.</div>

Accelerating the Discovery of Multilayer Nanostructures with Analytic Differentiation of the Transfer Matrix Equations

<div>Multilayer nanostructures represent an important class of materials with tunable optical and thermal radiative properties that can be leveraged for a wide range of energy applications. We present a theoretical framework for optimizing the geometry of such structures that utilizes gradients of various objective functions that are enabled through analytic differentiation of the transfer matrix equations. We demonstrate the usefulness of this method by applying it to the optimization of structures for incandescent light sources, and the global optimization of anti-reflective solar cell coatings.</div>