High Efficiency Solar Panel. Phase II. Gallium Arsenide.

Abstract

GaAs solar cell baseline design 7 3. LPE fabrication of GaAs solar cells 12 4. Hughes infinite solution epitaxy system with gm capacity 12 5. New substrate holder with large rectangular GaAs substrate 16 6. Cell yield for September 1977 through December 1978 20 7. GaAs solar cell fabrication process 15 8. Parallel gap welder: working area 25 9. Silver foil pattern with six tabs 26 10. Top view schematic of ultrasonic seam welder and supporting equipment 27 1i. Horizontal Bridgman growth 32 12. Boat supports 32 13. HESP II test plan 14. Cell performance histograms 15. Neutron irradiation test results 16. Electron irradiation test results 17. Temperature coefficient curves 51 18. Pull strength histograms 54 19. Antireflection coating and glassing results 59 20. Cell 3465 spectral reflectance 21. Intensity variation test 2. Temperature variation test Appendix A Illustrations I. The (AlGa) As-GaAs solar cell Z. Maximum power as a function of 1 MeV electron fluence 3. (AlGa) As-GaAs solar cell spectral response before and after I MeV electron irradiation 4. Short circuit current density versus 1 MeV electron radiation fluence, electrons/cm Z 5. Predicted (AlGa) As-GaAs solar cell short circuit current density versus 1 MeV electron radiation fluence ((AlGa)As layer thickness = 1. 0 Vm, initial diffusion length Lpo = 2 4m, Lno = 5 .m, and diffusion length damage constant KL = 7 x 10-8) 6. Short circuit current versus electron fluence level (1 MeV) 7. Maximum output power versus ' MeV electron fluence 8(a). (AIGa)As-GaAs solar cell spectral response versus 1 MeV electron radiation fluences 8(b). (AlGa)As-GaAs solar cell opectral response versus 1 MeV electron radiation fluence 81 vi LIST OF ILLUSTRATIONS Page I. GaAs HESP II Program schedule 2 2. GaAs solar cell baseline design 7 3. LPE fabrication of GaAs solar cells 12 4. Hughes infinite solution epitaxy system with 3000 gm capacity 12 5. New substrate holder with large rectangular GaAs substrate 16 6. Cell yield for September 1977 through December 1978 20 7. GaAs solar cell fabrication process 8. Parallel gap welder: working area 25 9. Silver foil pattern with six tabs 26 10. Top view schematic of ultrasonic seam welder and supporting equipment 27 1i. Horizontal Bridgman growth 32 12. Boat supports 32 13. HESP II test plan 14. Cell performance histograms 15. Neutron irradiation test results 16. Electron irradiation test results 17. Temperature coefficient curves 51 18. Pull strength histograms 54 19. Antireflection coating and glassing results 59 20. Cell 3465 spectral reflectance 21. Intensity variation test 2. Temperature variation test Appendix A Illustrations I. The (AlGa) As-GaAs solar cell Z. Maximum power as a function of 1 MeV electron fluence 3. (AlGa) As-GaAs solar cell spectral response before and after I MeV electron irradiation 4. Short circuit current density versus 1 MeV electron radiation fluence, electrons/cm Z 5. Predicted (AlGa) As-GaAs solar cell short circuit current density versus 1 MeV electron radiation fluence ((AlGa)As layer thickness = 1. 0 ...