In this work, a δ-doped dual MOS-capacitor (MOSCAP)(D-MOS) tunnel field effect transistor is proposed and investigated. The investigation has been carried out by varying the mole fraction of the SiGe δ-layer as well as by optimizing device dimensions like the effective oxide thickness, elevated channel thickness and epi-layer (thin intrinsic layer of the MOSCAP region) length and thickness. The optimized proposed device offers an ON current of 6.91× 10 6 A µm-1, I ON/I OFF of 4.83× 10 8, average sub-threshold swing of 18.67 mV dec− 1 and a maximum cut-off frequency of 1.28× 10 9 Hz. Furthermore, the application of the proposed device as a near-infrared optical sensor is studied using a photosensitive gate. It is observed that the device can sense closely spaced spectral wavelengths (∼ 100 nm) in the near-infrared region of the spectrum (1–0.7 µm) at low intensity of illumination (< 1 W cm− 2). The peak spectral sensitivities of 4.67× 10 3, 3.3× 10 3 and 9.77× 10 2 for the wavelength pairs (0.8 µm–0.7 µm),(0.9 µm–0.8 µm) and (1 µm–0.9 µm), respectively, are observed making it a highly sensitive optical sensor.