Highly sensitive broadband binary photoresponse in gateless epitaxial graphene on 4H-SiC

0544608 - ÚFCH JH 2022 RIV US eng J - Journal Article
Rathore, S. - Patel, Deepak Kumar - Thakur, Mukesh Kumar - Haider, Golam - Kalbáč, Martin - Kruskopf, M. - Liu, Ch.-I. - Rigosi, A. F. - Elmquist, R. E. - Liang, Ch.-T. - Hong, P.-D.
Highly sensitive broadband binary photoresponse in gateless epitaxial graphene on 4H-SiC.
Carbon. Roč. 184, OCT 2021 (2021), s. 72-81. ISSN 0008-6223. E-ISSN 1873-3891
R&D Projects: GA ČR(CZ) GX20-08633X
Institutional support: RVO:61388955
Keywords : silicon carbide * epitaxial graphene * binary response * broadband photodetector
OECD category: Physical chemistry
Impact factor: 11.307, year: 2021
Method of publishing: Limited access

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.
Permanent Link: http://hdl.handle.net/11104/0321442