Extended infrared absorption to 2.2 µm with Ge1−xSnx photodetectors grown on silicon

Thin film Ge
_1-x
Sn
_x
photodetectors fabricated on Si using a CMOS compatible process had responsivities at 1.55 μm of 6.59, 1.49, 2.63, and 0.84 mA/W for 0.9, 2.57, 3.2, and 7.0 % Sn. Spectral response for a Ge
_0.93
Sn
_0.07
photodetector had extended infrared response out to 2.2 μm.