Optical FOMs of extended-source DG–TFET photodetector in the visible range of the spectrum

In this paper, the optical characteristics of an extended-source double-gate tunnel field-effect transistor (ESDG–TFET)–based photodetector in the visible range of the spectrum at wavelength λ = (300–700) nm are investigated. The optical characteristics are examined at three specific wavelengths λ= 300, 500, and 700 nm at an intensity of 0.7 W cm−2. The optical characteristics of photosensors, such as absorption rate, generation rate, energy band profiles, transfer characteristics, sensitivity (S n), quantum efficiency (η), signal-to-noise ratio (SNR), and detectivity, are extracted according to the incident wavelength of light. The results reveal that the ESDG–TFET-based photosensor exhibits better optical characteristics at λ = 300 nm compared to at λ = 500 and 700 nm. Moreover, the proposed photosensor provides sensitivity, SNR, and responsivity in the order of 91.2, 79 (dB), and 0.74 (A Watt−1), respectively, at λ = 300 nm. Due to the high incident optical energy (E g) at 300 nm, the absorption and emission rates of this photosensor are significantly larger; consequently, it reports better optical characteristics. Finally, a comparative study of the proposed TFET-based photosensor with photosensors cited in the literature is summarized in tabular form. A comparison study in terms of spectral sensitivity between single-gate and double-gate ESDG–TFET is also reported. Moreover, an inverter circuit based on ESDG–TFET is designed, and the corresponding transient analysis is highlighted under both dark and light states.