Anti-phase domain-free GaAs on Ge substrates grown by molecular beam epitaxy for space solar cell applications
- Ohio State Univ., Columbus, OH (United States)
- Massachusetts Inst. of Tech., Cambridge, MA (United States)
Elimination of anti-phase domains (AFD`s) threading dislocations and uncontrolled interface diffusion are critical considerations for achieving maximum design flexibility and high efficiency in multi-bandgap III-V solar cells on Ge. In this paper, the authors identify critical growth steps to eliminate each of these problems and present an optimum molecular beam epitaxy (MBE) growth procedure which yields ADP-free, near-dislocation-free GaAs/Ge with greatly suppressed interdiffusion in both the GaAs overlayer and Ge substrate. For solid source MBE, elimination of APD`s requires a double-stepped, clean Ge surface and a prelayer consisting of a complete monolayer of either As or Ga. Correct additions can be observed and maintained by real-time in-situ monitoring to ensure reproducibility. Initiating growth at low temperature with migration enhanced epitaxy virtually eliminates Ge diffusion into GaAs and Ga diffusion into Ge, while As diffusion into Ge is substantially suppressed.
- OSTI ID:
- 304377
- Report Number(s):
- CONF-970953-; TRN: IM9905%%69
- Resource Relation:
- Conference: 26. IEEE photovoltaic specialists conference, Anaheim, CA (United States), 29 Sep - 3 Oct 1997; Other Information: PBD: 1997; Related Information: Is Part Of Conference record of the twenty sixth IEEE photovoltaic specialists conference -- 1997; PB: 1477 p.
- Country of Publication:
- United States
- Language:
- English
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