Direct Band Gap Ge0.85Sn0.15 Photodiodes for Room Temperature Gas Sensing

Ge
0.85
Sn
0.15
-based stacks were grown by reduced pressure chemical vapor deposition on 200 mm Si wafers. The resulting photodiodes showed detectivities above 10
⁸
cm.H
z
^1/2
.W
⁻¹
at 1.55 µm and a cutoff wavelength of 3.5 µm. This detection range opens up promising perspectives for future all-group-IV gas sensors.