A Novel Photosensitive Tunneling Transistor for Near-Infrared Sensing Applications: Design, Modeling, and Simulation

In this paper, a novel device structure, operating on the principle of band-to-band tunneling, has been designed for near-infrared (1-1.5 μm) multispectral optical sensing applications. A drain current model based on line tunneling approach has been developed to illustrate the device operation. The results of the model are compared with the simulated data for devices with similar dimension and structure, indicating good accuracy of the developed model. Spectral response of the device is studied by estimating the relative values of its transfer-as well as output-characteristics, and also by measuring the variation of threshold voltage, V
_T
and ON-state current, I
_ON
. V
_T
and I
_ON
are found to be sensitive to wavelength variations at moderate gate doping levels. V
_T
is found to increase by ~40 mV and I
_ON
decreases by 35% for a change of illumination wavelength from 1 to 1.5 μm at a gate doping of 1 × 10
¹⁸
cm
^-3
. Peak spectral sensitivity at an illumination intensity of 0.75 W/cm
²
is found to be 318.38, 2.02 × 10
³
, and 672.2 corresponding to the change in wavelength from (1-1.2 μm), (1.2-1.45 μm), and (1.45-1.5 μm), respectively.