Title :
High-temperature performance and radiation resistance of high-efficiency Ge and Si0.07Ge0.93 solar cells on lightweight Ge substrates
Author :
Venkatasubramanian, R. ; Timmons, M.L. ; Pickett, R.T. ; Colpitts, T.S. ; Hancock, J.A. ; Hills, J.S. ; Hutchby, J.A.
Author_Institution :
Research Triangle Inst., Research Triangle Park, NC, USA
Abstract :
Ge and Si0.07Ge0.93 alloys are potential candidates for low-bandgap junctions in multijunction solar cells. The radiation resistance of these materials to 1 MeV electrons has been measured, yielding end-of-life/beginning-of-life ratios of about 0.85 at a fluence of 1016 electrons/cm2. For Ge, the temperature coefficient of efficiency has been determined to be -0.106%/°C under a full AM0 spectrum and -0.048%/°C under a GaAs filter. Si0.7Ge0.93 cells have shown no performance degradation after exposure to temperatures as high as 500°C, and the temperature coefficient of efficiency for Si0.07 Ge0.93 junctions is about -0.045%/°C, about the same as Si in spite of a lower bandgap by almost 200 meV
Keywords :
Ge-Si alloys; electron beam effects; elemental semiconductors; germanium; solar cells; AM0 spectrum; Ge solar cells; Si0.07Ge0.93 solar cells; electron radiation; high temperature performance; high-efficiency; lightweight Ge substrates; low-bandgap junctions; multijunction solar cells; radiation resistance; temperature coefficient; Degradation; Electrical resistance measurement; Electrons; Filters; Gallium arsenide; Germanium alloys; Photonic band gap; Photovoltaic cells; Silicon alloys; Temperature;
Conference_Titel :
Photovoltaic Specialists Conference, 1991., Conference Record of the Twenty Second IEEE
Conference_Location :
Las Vegas, NV
Print_ISBN :
0-87942-636-5
DOI :
10.1109/PVSC.1991.169187
