Integration of Silica Aerogel Film as Rear Reflector to Silicon Solar Cells and Anti-Reflective Coating to Solar Panels

Date

2023-9-07

Author

Koçak, Damla

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

240
views

0
downloads

Cite This

The photovoltaic (PV) market is dominated by silicon solar cells despite silicon’s indirect band gap and thus being a non-ideal absorber. Due to the less-than-ideal circumstances, numerous approaches have been developed to improve silicon solar cells' power conversion efficiency by light management. These include anti-reflective coatings (ARCs), pyramidal texturing for multiple internal reflections, or reflectors to reduce parasitic absorption in full-area rear metal. This work proposes that silica aerogel thin film is very convenient as a rear reflector layer in silicon solar cells and an ARC for PV modules due to its optical properties (its low refractive index which is ~1.18). Aerogel thin films also benefit from low-cost fabrications (no vacuum required) at room temperature. As rear reflector, silica aerogel thin film has been integrated into silicon heterojunction (SHJ) and passivated emitter rear contact (PERC) types of solar cells. The spin-coated aerogel has been shown to increase the short-circuit current density by ~0.25 mA cm-2 compared to the reference, the state-of-the-art SHJ solar cell, resulting in a reduction of the indium content in the transparent conductive oxide layer by more than 50%. It has also been demonstrated that surface morphology helps to create electronic conduction via metal contact on the rear side without any additional process. Additionally, we have integrated silica aerogel thin films into large area (~156 x 156 mm2) PERC cells by spray coating and show that silica aerogel could be an alternative and promising material as a rear reflector for PERC applications. Finally, we have demonstrated that silica aerogel thin films can provide transmittance above 95% when deposited on glass substrates, and modifying silica aerogels with hexamethyldisilazane can also achieve excellent hydrophobicity (~140o; nearly superhydrophobic). Photon management by cost-effective silica aerogels both as rear reflector of silicon solar cells and ARC for PV modules are demonstrated as robust approaches for enhanced performance in PV technology.

Subject Keywords

aerogel, rear reflector, anti-reflective coating, silicon solar cell, solar panel

URI

https://hdl.handle.net/11511/105493

Collections

Graduate School of Natural and Applied Sciences, Thesis