(a) A p-i-n structure on silicon with quantum wells on relaxed buffer. (b) Effective absorption coefficient spectra of Ge/SiGe (10 nm Ge well and 16 nm Ge/Si0.15Ge0.85 barrier in this example) quantum wells on a relaxed Si0.1Ge0.9 buffer at room temperature. (c) Effective absorption coefficient spectra of strained Ge/SiGe (12.5 nm Ge well and 5 nm Si0.175Ge0.825 barrier in this example) quantum wells on a relaxed Si0.05Ge0.95 buffer under 0.5 V reverse bias at different temperatures. Figures are taken from [63].
