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 × 10¹⁸ cm^-3. Peak spectral sensitivity at an illumination intensity of 0.75 W/cm² is found to be 318.38, 2.02 × 10³, 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.