Design and Performance Study of Hybrid Graphene/HgCdTe Mid-Infrared Photodetector

Graphene has become a promising material for photodetection applications due to its superior electrical and optical properties with mobility excessed
$2\,\,\times10$
⁵
cm
²
V
⁻¹
s
⁻¹
in a broadband wavelength regime from UV to THz. However, the photoresponsivity is limited by the low absorption and ultrafast recombination of photogenerated carriers. Here, we designed and simulated a graphene/HgCdTe heterostructure with optimizing numerical parameters of hybrid graphene and HgCdTe. The independent effects of doping concentration, band gap, electron affinity, thickness, temperature, alloy composition etc. on photodetector performance have been studied. Generally, we have demonstrated that the combination of n-type HgCdTe and p-type graphene can construct a Schottky junction to effectively dissociate photogenerated electron-hole pairs, resulting in a highest external quantum efficiency of 69.06 % at
$3 \pmb \mu \text{m}$
and maximum high responsivity of 2.60 AW
⁻¹
in visible to mid-infrared wavelength region (
$0.5\pmb \sim 5.2 \pmb \mu \text{m}$
). These results contribute to offer a novel and versatile strategy for constructing the graphene/HgCdTe heterostructure infrared photodetectors.