Symmetry-breaking nanostructures on crystalline silicon for enhanced light trapping in thin film solar cells
| Autor: | Swapnadip Ghosh, Ethan C. Culler, Seok Jun Han, Brittany R. Hoard, Omar K. Abudayyeh, Sang M. Han, Jose E. Bonilla, Sang Eon Han |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Silicon business.industry chemistry.chemical_element 02 engineering and technology Substrate (electronics) 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Symmetry (physics) Solar cell efficiency Optics chemistry Photovoltaics 0103 physical sciences Optoelectronics Wafer Symmetry breaking Crystalline silicon 0210 nano-technology business |
| Zdroj: | Optics express. 24(26) |
| ISSN: | 1094-4087 |
| Popis: | We introduce a new approach to systematically break the symmetry in periodic nanostructures on a crystalline silicon surface. Our focus is inverted nanopyramid arrays with a prescribed symmetry. The arrangement and symmetry of nanopyramids are determined by etch mask design and its rotation with respect to the [110] orientation of the Si(001) substrate. This approach eliminates the need for using expensive off-cut silicon wafers. We also make use of low-cost, manufacturable, wet etching steps to fabricate the nanopyramids. Our experiment and computational modeling demonstrate that the symmetry breaking can increase the photovoltaic efficiency in thin-film silicon solar cells. For a 10-micron-thick active layer, the efficiency improves from 27.0 to 27.9% by enhanced light trapping over the broad sunlight spectrum. Our computation further reveals that this improvement would increase from 28.1 to 30.0% in the case of a 20-micron-thick active layer, when the unetched area between nanopyramids is minimized with over-etching. In addition to the immediate benefit to solar photovoltaics, our method of symmetry breaking provides a useful experimental platform to broadly study the effect of symmetry breaking on spectrally tuned light absorption and emission. |
| Databáze: | OpenAIRE |
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