Photon frequency management for trapping & concentration of sunlight
This paper considers a range of techniques which - within the realm of classical optics - can be used to enhance light capture as a first step in photovoltaic energy conversion. Examples include a simple case of downshifting, fluorescent collectors which reduce the size of a light beam, and a novel...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
2012-01-30.
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| Subjects: | |
| Online Access: | Get fulltext |
| Summary: | This paper considers a range of techniques which - within the realm of classical optics - can be used to enhance light capture as a first step in photovoltaic energy conversion. Examples include a simple case of downshifting, fluorescent collectors which reduce the size of a light beam, and a novel form of light trapping to increase the path length of light within the solar cell. The results are discussed using a thermodynamic framework where the energy exchange with an absorbing/fluorescent medium allows the entropy of the captured photon gas to be lowered, reducing the étendue of the emitted beam. We show that frequency management represents a powerful tool, allowing enhancement in light trapping above the Yablononovitch limit, leading to potentially highly efficient but very thin crystalline silicon solar cells. |
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