Enhancing the brightness of electrically driven single-photon
sources using color centers in silicon carbide
Igor A. Khramtsov
, Andrey A. Vyshnevyy
and Dmitry Yu. Fedyanin
Practical applications of quantum information technologies exploiting the quantum nature of light require efﬁcient and bright true
single-photon sources which operate under ambient conditions. Currently, point defects in the crystal lattice of diamond known as
color centers have taken the lead in the race for the most promising quantum system for practical non-classical light sources. This
work is focused on a different quantum optoelectronic material, namely a color center in silicon carbide, and reveals the physics
behind the process of single-photon emission from color centers in SiC under electrical pumping. We show that color centers in
silicon carbide can be far superior to any other quantum light emitter under electrical control at room temperature. Using a
comprehensive theoretical approach and rigorous numerical simulations, we demonstrate that at room temperature, the photon
emission rate from a p–i–n silicon carbide single-photon emitting diode can exceed 5 Gcounts/s, which is higher than what can be
achieved with electrically driven color centers in diamond or epitaxial quantum dots. These ﬁndings lay the foundation for the
development of practical photonic quantum devices which can be produced in a well-developed CMOS compatible process ﬂow.
npj Quantum Information (2018) 4:15 ; doi:10.1038/s41534-018-0066-2
Silicon carbide has been a recognized material for high-power and
high-temperature electronics for several decades.
At the same
time, despite the fact that light emission from semiconductors was
for the ﬁrst time observed from silicon carbide
yellow light emitting diodes were serially produced in the USSR in
the 1970s, for a long time SiC could not ﬁnd applications in the
optoelectronics of the XXI century. Due to the indirect bandgap
and thus low efﬁciency of light-matter interaction, SiC could not
compete with other semiconductor materials. However, recently it
attracted great research interest owing to the progress in an
entirely different ﬁeld of research.
After the ﬁrst studies of color centers in diamond,
become clear that point defects in the crystal lattice of dielectrics
and wide-bandgap semiconductors can be efﬁciently used in
quantum information technologies. These defects can be created
in diverse solid-state structures. At the same time, their optical
properties are much closer to the properties of isolated atoms and
molecules than those of quantum dots.
This gives a unique
opportunity to exploit the quantum optics effects at room
Silicon carbide, as well as diamond, can host diverse color
centers, such as carbon antisite-carbon vacancy complexes
silicon vacancies (V
nitrogen-vacancy (NV) centers,
silicon antisite-stacking fault
and tiny polytype inclusions.
defects in the crystal lattice of silicon carbide can be excited
optically and emit single photons on demand.
ever, the greatest advantage of silicon carbide over diamond and
recently emerged 2D materials
is its semiconductor properties.
SiC can be efﬁciently doped with both donors and acceptors and
demonstrate distinct electron and hole conductivity.
SiC devices can be fabricated in a well-developed CMOS
compatible process ﬂow.
These advantages are very promising
for the design and development of practical electrically-driven
devices for quantum information and communication systems,
particularly for the development of electrically pumped single-
which can operate at room temperature.
Implementation of electrical pumping is essentially important for
practical single-photon sources since optically pumped devices
are much less energy efﬁcient and are more difﬁcult to be
integrated on a chip.
Another advantage of silicon carbide is
that SiC is an indirect bandgap semiconductor material, which
ensures a low background luminescence level due to radiative
band-to-band transitions, which are unavoidable in electrically-
pumped devices at high injection levels. The result of the recent
intense research efforts was the demonstration of single-photon
emission from color centers in silicon carbide under electrical
pumping at room temperature.
The measured brightness of
these emitters was higher than that of the electrically pumped
color centers in diamond
and zinc oxide,
as well as
at room temperature, but lower than that of
the optically pumped color centers.
Further research aimed at
developing practical single-photon sources urgently needs an
understanding of the physics behind the process of photon
emission from a single color center in SiC under electrical
pumping and knowledge about how the demonstrated record
emission characteristics can be further improved.
Here, we perform a rigorous theoretical and numerical study of
single-photon electroluminescence of color centers in a silicon
carbide diode and predict the photon emission rate and the
correlation between emitted photons. Using a comprehensive
computational approach, we perform 2D numerical simulations of
4H-SiC single-photon emitting diode. We demon-
strate a highly nonlinear dependence of the photon emission rate
on the pump current, which can unexpectedly turn into a linear
Received: 12 August 2017 Revised: 5 January 2018 Accepted: 19 January 2018
Laboratory of Nanooptics and Plasmonics Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russian Federation
Correspondence: Dmitry Yu. Fedyanin (email@example.com)
Published in partnership with The University of New South Wales