Optimal design of ultra‐broadband, omnidirectional, and polarization‐insensitive amorphous silicon solar cells with a core‐shell nanograting structure

Abstract

We systematically investigated the optical behaviors of an amorphous silicon solar cell with a core‐shell nanograting structure. The horizontally propagating Bloch waves and Surface Plasmon Polariton waves lead to significant absorption enhancements and consequently short‐circuit current enhancements of this structure, compared with the conventional planar one. The perpendicular carrier collection makes this structure optically thick and electronically thin. An optimal design is achieved through full‐field numerical simulation, and a physical explanation is given. Our numerical results show that this configuration has ultra‐broadband, omnidirectional, and polarization‐insensitive responses and has a great potential in photovoltaics. Copyright © 2012 John Wiley & Sons, Ltd.

High-Efficiency Plasmonic Metamaterial Selective Emitter Based on an Optimized Spherical Core-Shell Nanostructure for Planar Solar Thermophotovoltaics

“…1b, the W nanosphere radius, the period, the middle SiO 2 layer thickness, and the W cover layer thickness are labeled r 1 , p, h 1 , and h 2 , respectively. Such core-shell nanostructure is different from not only those employed in nanolasing/luminescence applications, e.g., gold/silica/dye core-shell nanoparticles [26], a cadmium sulfide/silica/silver core-shell nanowire [27], a silicon/silica/silver core-shell nanowire [28], but also those used in photovoltaic applications, e.g., our previously reported thin film solar cell based on an amorphous silicon/gold core-shell nanograting [29], a silver/amorphous silicon core-shell single-nanowire solar cell [30]. All those nanostructures are based on a metal-dielectric core-shell nanostructure, consisting of only one metallic nanostructure as either the core [26,27,30] or the shell [28,29].…”

“…Such core-shell nanostructure is different from not only those employed in nanolasing/luminescence applications, e.g., gold/silica/dye core-shell nanoparticles [26], a cadmium sulfide/silica/silver core-shell nanowire [27], a silicon/silica/silver core-shell nanowire [28], but also those used in photovoltaic applications, e.g., our previously reported thin film solar cell based on an amorphous silicon/gold core-shell nanograting [29], a silver/amorphous silicon core-shell single-nanowire solar cell [30]. All those nanostructures are based on a metal-dielectric core-shell nanostructure, consisting of only one metallic nanostructure as either the core [26,27,30] or the shell [28,29]. The metallic loss must be minimized to a fairly low level, but meanwhile, the optical field must be confined tightly in the active semiconducting materials so as to enhance lasing/luminescence [26][27][28] or absorption [29,30] in it.…”

“…All those nanostructures are based on a metal-dielectric core-shell nanostructure, consisting of only one metallic nanostructure as either the core [26,27,30] or the shell [28,29]. The metallic loss must be minimized to a fairly low level, but meanwhile, the optical field must be confined tightly in the active semiconducting materials so as to enhance lasing/luminescence [26][27][28] or absorption [29,30] in it. In contrast, in order to enhance the thermal emission in the short wavelength range, we aim to confine the optical field in high-loss materials, i.e., W in this work.…”

Broadband Absorption and Efficient Hot-Carrier Photovoltaic Conversion based on Sunlight-induced Non-radiative Decay of Propagating Surface Plasmon Polaritons

“…With this model, partial absorptions in both the top and bottom Au films, η top ( λ ) and η bot ( λ ), can be obtained by integrating the square of electric field intensity with the imaginary part of the dielectric constants of Au over different areas and normalized by the incident light power, as derived previously in ref. 38.…”

Turn a Highly-Reflective Metal Into an Omnidirectional Broadband Absorber by Coating a Purely-Dielectric Thin Layer of Grating

“…A hybrid dielectric-metal core-shell grating structure over a metallic substrate was used in Ref. [32] to achieve broadband, omnidirectional, and polarization-independent absorption by combining two kinds of optical modes, namely, Bloch and SPP modes.…”