An optimized surface plasmon photovoltaic structure using energy transfer between discrete nano-particles

Abstract

Surface plasmon enhancement has been proposed as a way to achieve higher absorption for thin-film photovoltaics, where surface plasmon polariton(SPP) and localized surface plasmon (LSP) are shown to provide dense near field and far field light scattering. Here it is shown that controlled far-field light scattering can be achieved using successive coupling between surface plasmonic (SP) nano-particles. Through genetic algorithm (GA) optimization, energy transfer between discrete nano-particles (ETDNP) is identified, which enhances solar cell efficiency. The optimized energy transfer structure acts like lumped-element transmission line and can properly alter the direction of photon flow. Increased in-plane component of wavevector is thus achieved and photon path length is extended. In addition, Wood-Rayleigh anomaly, at which transmission minimum occurs, is avoided through GA optimization. Optimized energy transfer structure provides 46.95% improvement over baseline planar cell. It achieves larger angular scattering capability compared to conventional surface plasmon polariton back reflector structure and index-guided structure due to SP energy transfer through mode coupling. Via SP mediated energy transfer, an alternative way to control the light flow inside thin-film is proposed, which can be more efficient than conventional index-guided mode using total internal reflection (TIR).

Plasmonic materials for energy: From physics to applications

“…One possible approach to alleviate both sources of losses is to add thin insulating layers between plasmonic structures and active PV layers [143] or thin insulating shells enclosing metal nanoparticle cores [137,141]. Further exploration of plasmonic structures that maximize energy recycling outside of the metal volume [62][63][64]144] is also expected to significantly reduce the dissipation losses and to improve performance of PV cells and SP-enhanced solid-state light sources.…”

“…This makes possible trapping passing photons into optical vorticesnanoscale areas of circulating flow of optical energy around the localized phase singularities in the LSP near field ( Fig. 2(f)) [62][63][64]. If these vortices are engineered to re-circulate optical energy outside of the volume of the particles, metal dissipative losses can be significantly reduced.…”

An efficient plasmonic photovoltaic structure using silicon strip-loaded geometry

“…Light absorption in surface plasmon-inspired thin film solar cells can also be increased by transferring the incident solar energy between discrete metal nano-particles to excite modes spreading throughout the structure [11]. This technique achieves a significant absorption enhancement even without a reflective back contact, but impact of relative positions of discrete metal nano-particles and accuracy of dimensions make it quite difficult to fabricate.…”

Multilayer nanoparticle arrays for broad spectrum absorption enhancement in thin film solar cells

“…Multiple arrays of nanostructures placed either on the front, rear or both are used to further enhance the absorption efficiency [11][12][13]. The phenomenon of energy transfer between discrete nano-structures located at the surface and active region of a solar cell is used to control the flow of energy and improve absorption efficiency [14]. In these cases, enhancing the quantum efficiency has been considered over limited bands of wavelengths.…”