LetterreSeArCH
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in Extended Data Fig.6c, d. To test the entire harvesting system, we
approached a commercial Wi-Fi-band transmitter antenna (powered
by a signal generator with input power of about 2mW) to the inte-
grated MoS
2
rectenna. The flexible MoS
2
rectenna was successful in
wirelessly harvesting the RF power in the Wi-Fi channel (5.9GHz)
and generated a rectified output voltage of up to 250mV (distance
from transmitter antenna, about 2.5cm). With the demonstrated cutoff
frequency (10GHz) fully covering the Wi-Fi band, our phase-engi-
neered MoS
2
Schottky diode enabled the experimental demonstration
of a fully flexible rectenna operating as a Wi-Fi-band RF energy har-
vester (IEEE 802.11 standards). The complete flexibility of the MoS
2
rectenna is a critical advantage compared with rigid-diode technolo-
gies because it could enable the development of electronics with form
factors that allow seamless integration with objects of arbitrary shapes.
Fig. 3 | MoS
2
phase-junction rectenna as a wireless RF energy harvester.
a, Output voltage as a function of the input RFpower delivered to the
device at four different frequencies (2.4GHz, 5.9GHz, 10GHz and
15GHz). The corresponding circuit diagram is shown in Extended Data
Fig.5a. b, Power efficiency of MoS
2
rectifiers as a function of input power
in the Wi-Fi band. c, Output voltage as a function of frequency of the
input signal for RF power P
RF
=5mW. d, Illustration of a flexible rectifier
based on a MoS
2
phase junction, integrated with a flexible Wi-Fi band
antenna for wireless energy harvesting. The Wi-Fi-band a.c. signal from
the antenna is rectified into a d.c. signal by the MoS
2
rectifier. Shown are
the illustrativeI–t curves corresponding to the a.c. and d.c. currents (blue
and red arrow, respectively). e, Photograph of a MoS
2
rectenna on Kapton.
The right panel shows a zoom-in of the region of the MoS
2
rectifier. Scale
bar, 100μm.
Antenna
metal
Antenna
metal
MoS
2
diode
e
Wi-Fi bands
0.1110
Frequency (GHz)
Antenna
Wi-Fi band
radiation
Load
t
I
G
G
d
–20 –15 –10 –5 0510 –20 –15 –10 –5 0510
0
1
2
3
2.4 GHz
5.9 GHz
10 GHz
15 GHz
V
out
(V)
V
out
(mV)
P
RF
(dBm)
0
10
20
30
40
P
RF
(dBm)
2.4 GHz
5.9 GHz
Power efciency (%)
f
c
= 10 GHz
t
I
10
1
10
2
10
3
10
4
MoS
2
2H–1T
phase junction
Fig. 4 | Demonstration of the MoS
2
-based mixer operating in the
gigahertz range. The output signals are measured by a spectrum analyser
(Keysight N9020A) with an input impedance of 50Ω. a, Frequency
conversion by an RF mixer with two inputs: an RF signal with frequency
f
RF
and a local oscillator signal with frequency f
LO
. A signal with
frequencies f
IF
=f
RF
f
LO
can be generated at the output of the RF mixer.
b, Experimental demonstration of frequency conversion by a MoS
2
-based
gigahertz mixer. The RF and local oscillator frequencies are f
RF
=10.4GHz
and f
LO
=8GHz, respectively. The downconverted and upconverted
intermediate frequencies are f
IF
=2.4GHz and f
IF
=18.4GHz,
respectively. c, Frequency conversion by a MoS
2
-based gigahertz mixer.
The RF and local oscillator frequencies are f
RF
=1.4GHz and f
LO
=1GHz,
respectively. The downconverted and upconverted intermediate
frequencies are f
IF
=0.4GHz and f
IF
=2.4GHz, respectively.
Mixing
Pd Au
2H MoS
2
1T/1T′ MoS
2
–60
510
Power (dBm)
Power (dBm)
Frequency (GHz)Frequency (GHz)
15 20 25 0.51.0 1.52.0 2.5
–40
–20
0
–60
–80
–40
–20
0
I
tt
t
t
I
I
I
f
LO
= 8 GHz
f
LO
= 1 GHz
f
RF
= 10.4 GHz
f
RF
= 1.4 GHz
f
RF
– f
LO
=
2.4 GHz
f
RF
– f
LO
=
0.4 GHz
f
RF
+ f
LO
= 18.4 GHz
f
RF
+ f
LO
= 2.4 GHz
Radiofrequency (f
RF
)
Local oscillator (f
LO
)
Downconversion
f
RF
– f
LO
Upconversion
f
RF
+ f
LO
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