The Group IV Photonics (GFP) which include an alloy of Si, Ge & Sn that gives a direct bandgap material (GeSn, SiGeSn) in near and mid-IR region used as an active material in photonics devices. The multiple quantum well SiGeSn/GeSn transistor laser structure is considered in this paper and performance parameters are evaluated for the same. The result shows that the threshold base current density (2.6 kA/cm2) for the proposed device initially decreases with increasing number of quantum well (QW) and later on it saturates. The current gain and output photon density of the device decreases and increases respectively, with increasing number of QW.
In this work carrier transport mechanism in strain balanced SiGeSn/GeSn QWIP is studied to obtain the frequency response. Initially, a QWIP model is proposed in which a 76Å thick Ge0.83Sn0.17 layer is sandwiched between two tensile strained Si0.09Ge0.8 Sn0.11 layers to form a type-I single strain balanced quantum-well infrared photodetector (SQWIP). The rate equation in quantum well and continuity equation over the well are solved simultaneously to obtain frequency response. The 3dB bandwidth obtained from frequency response is evaluated as 47 GHz at zero bias which increased with the applied bias. Also, the effect of bias dependent escape rates of carrier from the quantum well on the 3dB bandwidth is studied.
In this work we present an analysis of frequency response of Si-Si0.12Ge0.73Sn0.15/Si0.11Ge0.73Sn0.16 n-p-n mid-infrared transistor laser (TL) with strain balanced Ge0.85Sn0.15 quantum well (QW) in the base. The frequency response of TL for common base (CB) configuration is calculated from small signal relationship between the photon density (s(jω)) and emitter current density ( je(jΩ)) by solving laser rate equation and continuity equation considering the virtual states as a conversion mechanism. The intrinsic response of TL with and without quantum capture and escape effect of carriers on modulation bandwidth are also shown. Further, bandwidth of TL in CB configuration is obtained as ~4.5 GHz at 2 mA bias current with zero resonance and it increases with larger escape time and reduced capture time of carrier in QW.