A new kind of transparent and self-cleaning film for solar cells

Abstract

A kind of one step and in situ etching method is developed to fabricate a highly optically transparent and flexible self-cleaning superhydrophobic film (SSF). This SSF exhibits a very rough surface morphology with hierarchical structure, which makes it have a contact angle of 154.6° and a sliding angle of smaller than 1°. And the SSF can also be self-cleaned in the wind. The SSF hierarchical structure scatters the incident light, but it almost doesn't attenuate the light. So the SSF has antireflection properties and a high light transmittance of 94%. The excellent self-cleaning property, high light transmittance and antireflection property mean that the SSF greatly enhances the performance of solar cells in practical working conditions. The solar cell's efficiency maintains at 95.8% of its initial value after covering with the SSF, which is about 1.7 times higher than that of the solar cell covered with dust, as in practical conditions.

Cleaning of Floating Photovoltaic Systems: A Critical Review on Approaches from Technical and Economic Perspectives

“…Many studies have been carried out to prove the soil-preventing features of superhydrophobic surfaces. A high optical transparent and flexible superhydrophobic film with a contact angle of 154.6 • has been fabricated in [87]. The PV panels' efficiency remains at 95.8% of its initial value after covering them with the superhydrophobic film, which is about 1.7 times higher than the same PV panels covered with dust in practical conditions.…”

Nanograting Structured Ultrathin Substrate for Ultraflexible Organic Photovoltaics

“…Nanopatterning onto the surfaces of polymer substrates provides additional functions including the lotus effect and self‐cleaning effect . Among these effects, modified optical characteristics such as the antireflection effect and plasmonics effect are beneficial especially for optical devices including light‐emitting diodes and photovoltaics …”

Transparent superhydrophilic and superhydrophobic nanoparticle textured coatings: comparative study of anti-soiling performance

“…Surface engineering of an anti-soiling (AS) feature on the reective surfaces of solar energy devices is important for stable solar energy harvesting, because accumulating dust layers induce signicant scattering and absorption of incident solar irradiation. [1][2][3][4][5][6][7][8][9] For example, concentrated solar power (CSP) technologies generate power by using mirrors to reect and concentrate a large area of sunlight onto a small area of a receiver. 1,7,[10][11][12][13][14] Maintaining clean mirror surfaces is important because CSP plants, mainly built in arid desert areas, experience severe dust accumulation.…”

“…In efforts to mitigate soiling and maintain clean surfaces, many studies have explored natural soiling of reective surfaces and environmentally friendly cleaning methods in the eld. [1][2][3]5,[8][9][10][11][12][13][14] Recent progress in nanotechnology (e.g., transparent superhydrophobic [SP] coatings 6,[15][16][17][18][19][20][21][22] ) suggests a potential breakthrough in a unique surface self-cleaning technology that could signicantly enhance the reliability and efficiency of solar panel glass and solar mirrors while drastically reducing cleaning and maintenance costs. A reduction in maintenance costs as a result of self-cleaning surfaces could have a signicant impact on energy harvesting.…”

“…Both types of coatings clean themselves through the action of water, the former by rolling water droplets off and the latter by forming water into a thin sliding layer that carries away dirt. 6,16,20 Recently, we reported that highly transparent SP nanoparticle (NP) -textured coatings exhibited excellent AS performance, which was associated with surface roughness at the scale of <100 nm and with a nonwetting property. 21,22 The rough surface structure of the SP NP coatings provided an intrinsic capability to repel small dust particles by reducing the adhesive force between dust particles and the coated surface.…”