Si-based High Responsivity Germanium-Tin MQW pin Photodetectors for Broadband Applications

Abstract

We report a novel vertical p-i-n photodiode with a Ge 0.87 Sn 0.13 /Ge 0.92 Sn 0.08 multiple-quantum-well (MQW) with an additional i – GeSn(Sn = 9%) layer on a strain-free Ge virtual substrate on Si-substrate. i – GeSn is considered to elongate the photon-absorption path (PAP). Thereby, a high spectral responsivity (SR) of 0.27A/W at -3V was achieved at 3050 nm. With the incorporation of Ge 0.87 Sn 0.13 as the well and Ge 0.92 Sn 0.0S as barrier leads the cut-off wavelength up to 3370 nm.