Direct bandgap InP, GaAs, CdTe, and Ga0.5In0.5P solar cells containing backside mirrors as well as parasitically absorbing substrates are analyzed for their limiting open circuit voltage and power conversion efficiency with comparison to record solar cells. From the principle of detailed balance, it is shown quantitatively that mirror solar cells have greater voltage and power conversion efficiency than their substrate counterparts. Next, the radiative recombination coefficient and maximum radiative lifetime of GaAs mirror and substrate solar cells are calculated and compared to the nonradiative Auger and Shockley-Read-Hall (SRH) lifetimes. Mirror solar cells have greater radiative lifetime than their substrate variants. Auger lifetime exceeds radiative lifetime for both substrate and mirror cells while SRH lifetime may be less or greater than radiative lifetime depending on trap concentration and capture cross section. Finally, the change in free energy of the photogenerated carriers is analyzed in a comparison between InP, GaAs, CdTe, and Ga0.5In0.5P mirror and substrate solar cells in order to characterize the relationship between solar photon quality and free energy management in solar cells with differing bandgaps. Wider bandgap visible threshold Ga0.5In0.5P solar cells make better use of the available change in free energy of the photogenerated charge carriers, even when normalized to the bandgap energy, than narrower bandgap near-IR threshold InP, GaAs, and CdTe solar cells.
Details
- First Principle Analyses of Direct Bandgap Solar Cells With Absorbing Substrates Versus Mirrors
- Kirk, Alexander (Author)
- Kirk, Wiley P. (Author)
- Ira A. Fulton Schools of Engineering (Contributor)
- Digital object identifier: 10.1063/1.4829459
- Identifier TypeInternational standard serial numberIdentifier Value0021-8979
- Identifier TypeInternational standard serial numberIdentifier Value1089-7550
- Copyright 2013 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 114, 174507 (2013) and may be found at http://scitation.aip.org/content/aip/journal/jap/114/17/10.1063/1.4829459, opens in a new window.
Citation and reuse
Cite this item
This is a suggested citation. Consult the appropriate style guide for specific citation guidelines.
First principle analyses of direct bandgap solar cells with absorbing substrates versus mirrors Kirk, Alexander P. and Kirk, Wiley P., Journal of Applied Physics, 114, 174507 (2013), DOI: http://dx.doi.org/10.1063/1.4829459