Plasmonic-photonic arrays with aperiodic spiral order for ultra-thin film solar cells

Abstract

We report on the design, fabrication and measurement of ultra-thin film Silicon On Insulator (SOI) Schottky photo-detector cells with nanostructured plasmonic arrays, demonstrating broadband enhanced photocurrent generation using aperiodic golden angle spiral geometry. Both golden angle spiral and periodic arrays of various center-to-center particle spacing were investigated to optimize the photocurrent enhancement. The primary photocurrent enhancement region is designed for the spectral range 600nm-950nm, where photon absorption in Si is inherently poor. We demonstrate that cells coupled to spiral arrays exhibit higher photocurrent enhancement compared to optimized periodic gratings structures. The findings are supported through coupled-dipole numerical simulations of radiation diagrams and finite difference time domain simulations of enhanced absorption in Si thin-films.

Structural and Spectral Properties of Deterministic Aperiodic Optical Structures

“…The history of mathematical phyllotaxis started in the first half of the nineteenth century when the brothers Auguste and Louis Bravais presented the first quantitative treatment of the phenomenon and recognized the relevance of the theory of continued fractions in this area (i.e., in the so-called cylindrical representation of phyllotaxis) [70]. Aperiodic Vogel spiral arrays of nanoparticles are rapidly emerging as a powerful nanophotonics platform with distinctive optical properties of interest to a number of engineering applications [42,58,[71][72][73][74][75][76][77][78]. This fascinating category of deterministic aperiodic media features circularly symmetric scattering rings in Fourier space entirely controlled by simple generation rules that induce a very rich structural complexity.…”

“…Moreover, it has been recently demonstrated that Vogel spiral arrays of metallic nanoparticles feature distinctive structural resonances and produce polarization insensitive, planar light diffraction across a broad spectral range, referred to as circular light scattering [72]. The planar diffraction property of Vogel spirals is ideally suited to enhance light-matter interactions on planar substrates and recently led to the demonstration of thin-film solar cell absorption enhancement, light emission, and second harmonic generation enhancement using metal-dielectric arrays [42,77,78]. Another fascinating feature of Vogel spiral diffracting elements is their ability to support distinctive scattering resonances encoding well-defined numerical sequences in the orbital angular momentum (OAM) of light [72][73][74][75], potentially leading to novel applications to singular optics and optical cryptography [79].…”

“…Critical modes manifest a power-law localization scaling with highly fragmented multifractal envelopes that were recently employed in multi-mode aperiodic lasing and optical sensing devices [36,[38][39][40][41]. The characteristic features that result from the richer optical phase space spanned by deterministic aperiodic designs found engineering applications to optical sensing, light emission and lasing, photo-detection, optical imaging and nonlinear optical devices [17,24,[42][43][44]. In addition to their importance for key technological applications, the study of deterministic aperiodic nanostructures (DANS) is a highly interdisciplinary and fascinating research field conceptually rooted in several branches of pure and applied mathematics, such as number theory [45,46], symbolic dynamics [47,48], and computational geometry (i.e., tiling and tessellation theory, point patterns and graph theory) [49][50][51][52].…”

Absorption enhancement of a-Si thin film solar cells through surface plasmon polaritons and cavity resonance

“…In order to find out the best structures ,a large number of research has been done, including the front gratings [2]、the back gratings [3]、the dual-gratings [4]、 and the photonic crystal. Besides, many researches focus on the arrangement of the particles ,including Gaussian disorder surface [5] and gold angle arrangement surface [6].…”

Experimental broadband absorption enhancement in silicon nanohole structures with optimized complex unit cells

“…Recently, however, alternative lighttrapping schemes have been proposed based on aperiodic photonic patterns. Among these proposals, several have investigated structures with complete aperiodicity [3][4][5][6] of either random 3,4,6 or deterministic 5 nature. Such structures were found to improve solar absorption, with the additional benefit of performance insensitivity to incidence angle and polarization.…”