Highly sensitive broadband binary photoresponse in gateless epitaxial graphene on 4H–SiC
Journal
Carbon
Journal Volume
184
Pages
72-81
Date Issued
2021
Author(s)
Rathore S
Patel D.K
Thakur M.K
Haider G
Kalbac M
Kruskopf M
Liu C.-I
Rigosi A.F
Elmquist R.E
Hong P.-D.
Abstract
Due to weak light-matter interaction, standard chemical vapor deposition (CVD)/exfoliated single-layer graphene-based photodetectors show low photoresponsivity (on the order of mA/W). However, epitaxial graphene (EG) offers a more viable approach for obtaining devices with good photoresponsivity. EG on 4H–SiC also hosts an interfacial buffer layer (IBL), which is the source of electron carriers applicable to quantum optoelectronic devices. We utilize these properties to demonstrate a gate-free, planar EG/4H–SiC-based device that enables us to observe the positive photoresponse for (405–532) nm and negative photoresponse for (632–980) nm laser excitation. The broadband binary photoresponse mainly originates from the energy band alignment of the IBL/EG interface and the highly sensitive work function of the EG. We find that the photoresponsivity of the device is > 10 A/W under 405 nm of power density 7.96 mW/cm2 at 1 V applied bias, which is three orders of magnitude greater than the obtained values of CVD/exfoliated graphene and higher than the required value for practical applications. These results path the way for selective light-triggered logic devices based on EG and can open a new window for broadband photodetection. ? 2021 Elsevier Ltd
Subjects
Binary response; Broadband photodetector; Epitaxial graphene; Silicon carbide; Buffer layers; Chemical vapor deposition; Graphene devices; Logic devices; Photodetectors; Photons; Silicon carbide; Binary response; Broadband photodetector; Chemical vapour deposition; Epitaxial graphene; Light-matter interactions; Photoresponses; Photoresponsivity; Single layer; Source of electrons; Weak lights; Graphene
SDGs
Type
journal article