Optical Performance Dependence on Area of Illumination (AoI): A Conceptual Study of TFET based Phototransistor

This article presents the study of Germanium gated Tunnel Field effect transistor at 1550nm (NIR) communication window. Germanium layer works as a photogate layer over the complete channel with finite absorption at 1550nm. The device has been explored using ATLAS SILVACO TCAD tool. Due to its low subthreshold swing, low voltage operation, low off current and high I
on
/I
off
ratio of TFET makes it a potential device for highly sensitive photodetector for optical interconnects. An exhaustive study concerning the impact of Direction of Illumination (Area of Illumination) has been carried out for optical properties of the device. The measured illuminated drain current characteristics demonstrate a higher drain current for large Area of illumination. Ultra low noise current (Off Current) of
$4.02\times 10^{-17}\mathrm{A}$
, Illumination current of
$6.54\times 10^{-7}\mathrm{A}$
, Great Sensitivity of
$1.63\times 10^{10}$
, Responsivity of 2.8 A/W and Detectivity of
$3.49\times 10^{13}$
Jones proves it a prospective improvement in the overall optical performance.