The spectral p-n junction model for tandem solar-cell design

Journal Article · Sun Feb 01 04:00:00 EST 1987 · IEEE Trans. Electron Devices; (United States)

DOI:https://doi.org/10.1109/T-ED.1987.22916· OSTI ID:5629198

Nell, M E; Barnett, A M

Tandem solar cells can have significantly higher efficiencies than single-junction solar cells because they convert a larger fraction of the incident solar spectrum to electricity. For the design of tandem solar cells the spectral p-n junction model is proposed. It is based on tabulated standard spectra, on the fit of experimentally achieved open-circuit voltages, and assumes a quantum efficiency of unity. By consistent treatment of the energy gap in the diode equation, the model can be quantitatively applied to all tandem solar-cell systems. The special form and use of the reverse saturation current density is discussed in detail. The spectral p-n junction model is rigorously applied based on accepted standard spectra. The tandem solar-cell performance limits based on the model are calculated. A quantitative expression for the increase in efficiency under concentration is derived. The limits predicted by the model are discussed for tabulated standard spectra. The highest achievable efficiency is 57.3 percent (AM1.5 global) without concentration of the incident light. The increase in efficiency under concentration is evaluated, and it is found that the relative change of the efficiency at any concentration X is linear with In (X).

• Research Organization: Institut fur Werkstoffe der Elektrotechnik, Technische Universitat Berlin, Jebensstrasse 1, 1000 Berlin 12
• OSTI ID: 5629198
• Journal Information: IEEE Trans. Electron Devices; (United States), Journal Name: IEEE Trans. Electron Devices; (United States) Vol. ED-34:2; ISSN IETDA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
DIRECT ENERGY CONVERTERS
EFFICIENCY
ENERGY EFFICIENCY
ENERGY GAP
EQUIPMENT
GRADED BAND GAPS
JUNCTIONS
MATHEMATICAL MODELS
P-N JUNCTIONS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMICONDUCTOR JUNCTIONS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTRA