Absorption enhanced thin‐film solar cells using fractal nano‐structures

Abstract

In this article, a new structure for development of thin film solar cells is proposed in which elements with fractal shapes are integrated inside the cell to enhance its performance in a wide range of wavelengths. Two different structures are studied. In the first structure, a metallic fractal nano-carpet is integrated inside the silicon layer in order to trap and absorb sunlight by exciting surface plasmon polaritons and local surface plasmons at different wavelengths. Numerical analysis shows that this technique increases the short circuit current provided by the cell by a factor of 2.40 for both TM and TE polarisations of the incident light. The second structure has an active layer shaped as a fractal structure, and absorbs sunlight through Mie and Fabry-Perot resonances occurring at different wavelengths. The short circuit current enhancement for this structure is 2.97 for both TM and TE polarisations of the incident light, representing a significant improvement when compared with the previous works. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Fractal Theory in Thin Films: Literature Review and Bibliometric Evidence on Applications and Trends

“…For instance, solar cells exhibiting fractal-like features have been said to perform better. Such solar cells exhibit higher absorption to solar than the normal solar cells and the fractal thin film structure enhances its performance in a wide range of wavelengths [23]. For example, Sierpinski (fractal) back-structure thin solar cells have been demonstrated to absorb more light than other types of solar cells [24].…”

Rotational freedom thin‐film solar cell using a reconfigurable nano‐antenna with 4‐Dimethyl‐Amino‐N‐methyl‐4‐Stilbazolium Tosylate

“…Directive nano-antennas integrated inside the solar cells could receive the visible light from the free space and improve the absorption [7,16,17]. The fractal structures trap sunlight at different wavelengths leading to near-unity absorption [18,19]. The effects of incorporating the random distribution of silicon nano-spheres inside the solar cell to improve the performance of the solar cells and increase their efficiency have been investigated in Refs.…”

“…In recent years, nanostructures have been applied to thinfilm solar cells to trap sunlight and increase photo-current generation [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The nanostructures inside the solar cell increase the optical path length of photons leading to absorption enhancement.…”

Energy recycling under ambient illumination for internet-of-things using metal/oxide/metal-based colorful organic photovoltaics

“…However, the availability of different colors is directly linked to the type of processing methods and variable costs for each active material, restricting the practical applications of semitransparent OPVs. A limited studies have employed color filters (CFs), including photonic arrays [19,20], Bragg reflectors [21,22], and surface plasmonic resonators [23,24] in conventional solar cells. Although they function as CFs, these techniques have some disadvantages such as high fabrication costs, structural complexity, and the poor electrical conductivities of dielectric materials.…”