K. Takahashi et al., CHARACTERISTICS OF GAAS SOLAR-CELLS ON GE SUBSTRATE WITH A PRELIMINARY GROWN THIN-LAYER OF ALGAAS, Solar energy materials and solar cells, 50(1-4), 1998, pp. 169-176
Characteristics of GaAs solar cell on Ge substrate with a new buffer l
ayer structure is reported. The buffer layer structure, which consiste
d of a preliminarily grown thin layer of AlxGa1-xAs and a 1 mu m thick
GaAs layer, was designed to obtain a high quality GaAs layer on Ge su
bstrate by metalorganic chemical vapor deposition (MOCVD). Performance
of a GaAs solar cell fabricated on Ge substrate with the buffer layer
structure was compared with that fabricated on Ge substrate with a co
nventional GaAs buffer layer and also that fabricated on GaAs substrat
e. A conversion efficiency of 23.18% (AM1.5G) was successfully obtaine
d for the cell fabricated on Ge substrate with the new buffer layer st
ructure, while it was 20.92% for the cell fabricated on Ge substrate w
ith the conventional GaAs buffer layer. Values of V-oc and J(sc) for t
he cell fabricated on Ge substrate with the new buffer layer structure
were approximately comparable to those of a 25.39% efficiency GaAs so
lar cell fabricated on GaAs substrate.