International Journal of Thermofluids (Aug 2021)
Modified solar cells with antireflection coatings
Abstract
Designing a solar cell that can harvest energy with a high level of efficiency is an important research topic. For improving the performance of solar cells, this paper introduces four proposed structures for solar cells and examines their efficiencies for potential production with low cost and high efficiency. In each model, the absorbent material is Borofloat glass and the antireflection coatings used are SiNx and sol-gel -based materials. The four proposed solar cell structures are as follows: (i) a three-layer solar cell in which a sol-gel film is used to match the refractive index between the glass substrate and air cladding; (ii) a four-layer solar cell in which a sol-gel film is used to match the refractive index between SiNx laid on top of a glass substrate and air cladding; (iii) a four-layer structure in which a sol-gel film topped with air cladding is used as a match between the glass and SiNx; and (iv) a four-layer solar cell in which two layers of SiNx are stacked between the glass and the air. A transfer-matrix method is used to solve for the total transmission and total reflection for all structures, and the effects of the film thicknesses and incidence angles are considered in each case. An analysis is carried out using Maple 17, and the results show that using a sol-gel material between glass and air gives almost zero reflection for a wide range of wavelengths, meaning that this can be used as a perfect absorbent and can therefore be recommended for high-efficiency solar cells. Using two layers of SiNx between the air and glass gives almost zero reflection at 600 nm, making this approach an outstanding candidate for solar cells with a maximum absorption of around 600 nm. The other two structures have lower values of transmission, meaning that they are good candidates for low-efficiency solar cells. However, further techno-economic studies of the proposed structures should be carried out, and that solar cell manufacturers should consider these structures.
