Abstract:
In this paper, p
+–bilayer graphene (BLG)/nHg0.7783Cd0.2217Te heterojunction based long wavelength
infrared (LWIR: 2-12 µm) photodetector is reported.
The LWIR radiations are absorbed in lightly doped nHg0.7783Cd0.2217Te active layer. The drift-diffusion
approach is used for the simulation of the device.
Different recombination mechanism models such as
Shockley-Read-Hall, Auger, and optical are considered
for computing dark current. The photodetector exhibits
dark current of 3.5 pA, photocurrent of 1.9 nA, and
Iph/Idark ratio of 543 at –1 V bias. The maximum external
quantum efficiency (QEext) of 88.38%, photocurrent
responsivity of 4.5 AW–1
, specific detectivity (D*
) of
1.8×1015 cmHz1/2W–1
, noise equivalent power (NEP) of
3.53×10–19 W, and the 3-dB bandwidth of about 64.8
GHz at –0.5 V is achieved at 77 K, confirms the
suitability of proposed photodetector for low noise
applications.
