Atlas Simulation of a Long-Infrared P+-N Homojunction Photodiode

This paper presents the Atlas simulation of two-dimensional (2D) and three-dimensional (3D) p
⁺
-n homojunction photodiode based on Hg
_1-x
Cd
_x=0.22
Te semiconductor material for operation in the long-infrared (LIR) spectral region (2-12 μm). The simulated photodiode has been studied at 77 and 300 K in terms of the various electro-optical parameters for example energy bandgap diagram, the electric field profile, the current densities, external quantum efficiency (QE
_ext
), and noise equivalent power (NEP) with respect to applied bias voltage, device thickness, and operating wavelength. The simulated 2D and 3D results are comparable with the results obtained from analytical equations based on drift-diffusion, tunneling and Chu's approximation techniques. The photodiode exhibits high electric field, low value of zero bias dark current density of 0.26 pA/cm
²
, better photocurrent density of 4.9 μA/cm
²
, 3-dB bandwidth of 104 GHz, high external quantum efficiency of 58.34% and low noise equivalent power of 2.5×10
^-16
W.