Low dark current high gain InAs quantum dot avalanche photodetectors monolithically grown on Si

Avalanche photodetectors (APDs) on Si operating at optical communication wavelength band are crucial for Si-based transceiver application. In this paper, we report the first O-band InAs quantum dot (QD) waveguide avalanche photodetectors monolithically grown on Si with a low dark current of 0.1 nA at unit gain and a responsivity of 0.234 A/W at 1.310 μm at unit gain (-5V). In the linear gain mode, the APDs have a maximum gain of 198 and show a clear eye diagram up to 8 Gbit/s. These QD-based APDs enjoy the benefit of sharing the same epitaxial layers and processing flow as QD lasers, which could potentially facilitate the integration with laser sources on Si platform.