Enhancing optoelectronic properties of SiC-grown graphene by a surface layer of colloidal quantum dots
Journal article, 2017

We report a simultaneous increase of carrier concentration, mobility and photoresponsivity when SiC-grown graphene is decorated with a surface layer of colloidal PbS quantum dots, which act as electron donors. The charge on the ionised dots is spatially correlated with defect charges on the SiC-graphene interface, thus enhancing both electron carrier density and mobility. This charge-correlation model is supported by Monte Carlo simulations of electron transport and used to explain the unexpected 3-fold increase of mobility with increasing electron density. The enhanced carrier concentration and mobility give rise to Shubnikov-de Haas oscillations in the magnetoresistance, which provide an estimate of the electron cyclotron mass in graphene at high densities and Fermi energies up to 1.2 x 10(13) cm(-2) and 400 meV, respectively.

Monte Carlo simulations

SiC-graphene

colloidal quantum dots

unipolar charge correlation

Author

O. Makarovsky

University of Nottingham

L. Turyanska

University of Lincoln

University of Nottingham

N. Mori

Osaka University

M. Greenaway

Loughborough University

University of Nottingham

L. Eaves

University of Nottingham

A. Patane

University of Nottingham

M. Fromhold

University of Nottingham

Samuel Lara Avila

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Sergey Kubatkin

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

R. Yakimova

Linköping University

2D Materials

2053-1583 (eISSN)

Vol. 4 3

Subject Categories

Physical Sciences

Nano Technology

DOI

10.1088/2053-1583/aa76bb

More information

Latest update

6/12/2018