Abstract
The effect of germanium fraction on the effective minority carrier lifetime (τeff) for epitaxial Si1xGex layers is extracted using measurements on amorphous(a) Si(n+)/crystalline(c)-Si 1xGex(p)/crystalline(c)-Si(p+) heterojunction solar cells with x = 0.25, 0.41 and 0.56. The τeff extracted for Si 0.75Ge0.25 is ∼1 μs, decreasing to ∼ 40 ns for Si0.44Ge0.56. In addition, the band-gap voltage offset (Woc) increases from 0.5 eV for Si to 0.65 eV for 56% Ge indicating an increase in non-radiative recombination consistent with the reduction in effective lifetime.
Original language | British English |
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Article number | 052119 |
Journal | AIP Advances |
Volume | 3 |
Issue number | 5 |
DOIs | |
State | Published - May 2013 |