5 research outputs found
Zn3As2 Nanowires and nanoplatelets: highly efficient infrared emission and photodetection by an earth abundant material
The development of earth abundant materials for optoelectronics and photovoltaics promises improvements in sustainability and scalability. Recent studies have further demonstrated enhanced material efficiency through the superior light management of novel nanoscale geometries such as the nanowire. Here we show that an industry standard epitaxy technique can be used to fabricate high quality II-V nanowires (1D) and nanoplatelets (2D) of the earth abundant semiconductor Zn3As2. We go on to establish the optoelectronic potential of this material by demonstrating efficient photoemission and detection at 1.0 eV, an energy which is significant to the fields of both photovoltaics and optical telecommunications. Through dynamical spectroscopy this superior performance is found to arise from a low rate of surface recombination combined with a high rate of radiative recombination. These results introduce nanostructured Zn3As2 as a high quality optoelectronic material ready for device exploration.T.B., P.C., Y.G., H.H.T., and C.J. acknowledge the Australian
Research Council. T.B., P.C., Y.G., H.H.T., and C.J. thank the
Australian National Fabrication Facility for access to the growth
and microscopy facilities and Centre for Advanced Microscopy
and Australian Microscopy and Microanalysis Research Facility
for access to microscopy facilities used in this work. Y.W., B.B.,
H.E.J., and L.M.S. acknowledge the financial support of the
National Science Foundation through grants DMR-1105362,
1105121, and ECCS-1100489
2D Semiconductor Nonlinear Plasmonic Modulators
A plasmonic modulator is a device that controls the amplitude or phase of
propagating plasmons. In a pure plasmonic modulator, the presence or absence of
a pump plasmonic wave controls the amplitude of a probe plasmonic wave through
a channel. This control has to be mediated by an interaction between disparate
plasmonic waves, typically requiring the integration of a nonlinear material.
In this work, we demonstrate the first 2D semiconductor nonlinear plasmonic
modulator based on a WSe2 monolayer integrated on top of a lithographically
defined metallic waveguide. We utilize the strong coupling between the surface
plasmon polaritons, SPPs, and excitons in the WSe2 to give a 73 percent change
in transmission through the device. We demonstrate control of the propagating
SPPs using both optical and SPP pumps, realizing the first demonstration of a
2D semiconductor nonlinear plasmonic modulator, with a modulation depth of 4.1
percent, and an ultralow switching energy estimated to be 40 aJ
Quantum Confined Stark Effect in a GaAs/AlGaAs Nanowire Quantum Well Tube Device: Probing Exciton Localization
In
this Letter, we explore the nature of exciton localization in single
GaAs/AlGaAs nanowire quantum well tube (QWT) devices using photocurrent
(PC) spectroscopy combined with simultaneous photoluminescence (PL)
and photoluminescence excitation (PLE) measurements. Excitons confined
to GaAs quantum well tubes of 8 and 4 nm widths embedded into an AlGaAs
barrier are seen to ionize at high bias levels. Spectroscopic signatures
of the ground and excited states confined to the QWT seen in PL, PLE,
and PC data are consistent with simple numerical calculations. The
demonstration of good electrical contact with the QWTs enables the
study of Stark effect shifts in the sharp emission lines of excitons
localized to quantum dot-like states within the QWT. Atomic resolution
cross-sectional TEM measurements and an analysis of the quantum confined
Stark effect of these dots provide insights into the nature of the
exciton localization in these nanostructures
Zn<sub>3</sub>As<sub>2</sub> Nanowires and Nanoplatelets: Highly Efficient Infrared Emission and Photodetection by an Earth Abundant Material
The development of earth abundant
materials for optoelectronics and photovoltaics promises improvements
in sustainability and scalability. Recent studies have further demonstrated
enhanced material efficiency through the superior light management
of novel nanoscale geometries such as the nanowire. Here we show that
an industry standard epitaxy technique can be used to fabricate high
quality II–V nanowires (1D) and nanoplatelets (2D) of the earth
abundant semiconductor Zn<sub>3</sub>As<sub>2</sub>. We go on to establish
the optoelectronic potential of this material by demonstrating efficient
photoemission and detection at 1.0 eV, an energy which is significant
to the fields of both photovoltaics and optical telecommunications.
Through dynamical spectroscopy this superior performance is found
to arise from a low rate of surface recombination combined with a
high rate of radiative recombination. These results introduce nanostructured
Zn<sub>3</sub>As<sub>2</sub> as a high quality optoelectronic material
ready for device exploration