Variable Band Gap Materials for Thermophotovoltaic Generators.
Abstract
Thermophotovoltaic (TPV) properties of InGaAs cells with band gaps of either 1.15 or 1.2 eV, GaAs cells, and Si cells were investigated. In particular, dark and illuminated current vs voltage characteristics were obtained for a number of these concentrator cells at cell temperatures ranging from 300 to 550 K and currents varying from 10 to the minus 8th power to 10 A. Based on these data, the temperature dependence of the TPV efficiency for each of these cells was inferred for a fixed value of the parasitic absorption of the below-band-gap energy photons. For a given weighted parasitic absorption of 5%, the InGaAs cells have a significantly higher TPV efficiency than the GaAs or Si cells. TPV efficiencies approaching 40% at 300 K and 26% at 500 K appear feasible for the InGaAs cells. Based on these data, it was calculated that the specific mass of a space-based nuclear-TPV energy conversion system would be 10 kg/KW if InGaAs cells with 5% weighted parasitic absorption were used. In addition, a theoretical model was developed for determining the optimum efficiency of single and multiple band gap cells in TPV energy conversion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1985
- Accession Number
- ADA161987
Entities
People
- John C. Bass
- Lawrence D. Woolf
- Norbert B. Elsner