Ultrasensitive Photoresponse of Graphene Quantum Dots in the Coulomb Blockade Regime to THz Radiation.
Nano Lett
; 20(7): 5408-5414, 2020 Jul 08.
Article
em En
| MEDLINE
| ID: mdl-32470310
ABSTRACT
Graphene quantum dots (GQDs) have recently attracted considerable attention, with appealing properties for terahertz (THz) technology. This includes the demonstration of large thermal bolometric effects in GQDs when illuminated by THz radiation. However, the interaction of THz photons with GQDs in the Coulomb blockade regime, i.e., single electron transport regime, remains unexplored. Here, we demonstrate the ultrasensitive photoresponse to THz radiation (from <0.1 to 10 THz) of a hBN-encapsulated GQD in the Coulomb blockade regime at low temperature (170 mK). We show that THz radiation of â¼10 pW provides a photocurrent response in the nanoampere range, resulting from a renormalization of the chemical potential of the GQD of â¼0.15 meV. We attribute this photoresponse to an interfacial photogating effect. Furthermore, our analysis reveals the absence of thermal effects, opening new directions in the study of coherent quantum effects at THz frequencies in GQDs.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article