Telecom InP-based quantum dash photodetectors grown on Si

Photodetectors on Si with high responsivity, large bandwidth, and multispectral operation are required for high data rate communications using Si photonics. We report characteristics of InP-based quantum dash (QDash) photodetectors with a p-i-n structure directly grown on (001) Si. Three layers of quantum dashes were grown on InP on Si templates and fabricated into waveguide photodetectors. The QDash photodetectors can operate from 1240 nm to 1640 nm, covering the entire telecommunication band. A low dark current density of 2.1 × 10−6 A/cm2, responsivities of 0.35 ± 0.05 A/W at 1550 nm and 0.94 ± 0.05 A/W at 1310 nm, and a 3-dB bandwidth of 10.3 GHz were demonstrated. Our results show that the QDash photodetectors grown on Si hold great potential for on-chip integration in Si-photonics.