Abstract
This work presents the high-performance Si/SiO2distributed Bragg reflector (DBR)-integrated lateral germanium (Ge) p-i-n photodetectors (PDs) for atmospheric gas sensing and fiber-optic telecommunication networks in the short-wave infrared (SWIR) regime. In addition, this study also proposes an opto-electronic compact small-signal noise equivalent circuit model (SSNECM) of the designed device to compute the signal-to-noise ratio (SNR) at the output of the detector. Various figure-of merits including current under dark and illumination, responsivity, detectivity, 3dB bandwidth, and the SNR of the proposed device are estimated at the room-temperature (RT) for an incident optical power of 0.5 μW. Furthermore, the impact of scaling of rib waveguide (WG) width and height on dark current, responsivity, and 3dB bandwidth are investigated to optimize the proposed device. The validation of the proposed model is done by comparing various parameters including dark current, responsivity, and detectivity of the designed device with other Ge PDs. The estimated results show the reduced trade-off between responsivity and 3dB bandwidth of the designed device. At λ=1550 nm, the proposed device achieves the high detectivity and SNR of >2X1011 Jones and 120 dB (up to 3 THz), respectively, with the bias voltage of -2V. These encouraging results pave the path for the future development of low noise and high-speed detectors for SWIR applications.