Nanopyramid Structures with Light Harvesting and Self- Cleaning Properties for Solar Cells

Abstract

In this chapter, inverted and upright nanopyramid structures with light-harvesting properties and self-cleaning hydrophobic surfaces suitable for solar cells are presented. Periodic nanopyramid structures with 400-700 nm features were fabricated using interference lithography and combined dry and wet etching processes. The inverted nanopyramids (INP) were applied at the front side of the solar cells using UV nanoimprint lithography. These structures provided effective light-trapping properties and led to oblique angle light scattering and a significant reduction in reflectance resulting in higher power conversion efficiency. The second type, the periodic upright nanopyramid (UNP) structures were applied on a glass substrate by UV nanoimprint process. The glass cover is also utilized as a protective encapsulant front layer. The use of the upright nanopyramid structured cover glass in the encapsulated solar cell has also enhanced the power conversion efficiency due to the antireflection and strong light-scattering properties compared to the bare cover glass. In addition, the upright nanopyramid structured cover glass exhibited excellent self-cleaning of dust particles by rolling down water droplets. These results suggest that the nanopyramid structures with light-harvesting and self-cleaning properties can improve the performance of different types of solar cells, including thin films and glass-based PVs.

Improved omnidirectional polarisation‐insensitive optical absorption and photoelectrochemical water splitting using aperiodic and tapered slanted, kinked and straight silicon nanowires

“…In slanted SiNWs, incoming light bounces back and forth within the wires, which results in increased optical path length inside the wires and allows nanowires to absorb more light 20 . Similarly, in the case of nano‐pyramids, oblique angle scattering increases the optical absorption 28 . It is clear from Figure 4B,C that with an increase in etching time (25–35 min) the length of the slanted SiNWs increased from 5.5 to 8.4 μm.…”

“…20 Similarly, in the case of nano-pyramids, oblique angle scattering increases the optical absorption. 28 A good antireflecting surface must show a low reflectance over a wide range of angles for both forms of light polarisation. [2] The contour plots of the measured reflectance spectra of the slanted SiNWs for a wide range of incidence angles for both polarisation states are shown in Figure 5A,B.…”

Research Progress of Plasmonic Nanostructure-Enhanced Photovoltaic Solar Cells

“…Therefore, to enhance light absorption and PCE of OPVs with a thicker active layer, the surface plasmon resonance effect might be utilized by introducing metallic nanoparticles [ 17 , 18 , 19 , 20 , 21 ]. Nanophotonic structures have the advantage of self-cleaning, because dust particles adversely affect solar cell efficiency by accumulating on the photovoltaic cell surface [ 22 , 23 , 24 ]. Nanostructures need to be engineered in such a way as to decrease optical losses at the front surface due to light reflection and enhance light transmittance.…”

Nanostructures for Light Trapping in Thin Film Solar Cells

“…In addition, incident light reaching the active absorber layer in solar cells can be interfered by dust particles in typical terrestrial environments and thus decreases the power conversion efficiency. Therefore, nanophotonic structures with a self-cleaning capability coating the solar cell are becoming necessary for sustainability and improved performance of the solar cells in typical terrestrial environments [15,16,17,18,19,20,21,22].…”