Flexible, Ultrathin and Transparent Sound-Emitting Devices Using
Silver Nanowire Film
—Supporting Information
He Tian,1, 1 Tian-Ling Ren,1,2,a) Dan Xie,1,2 Yi Yang,1,2 Yu-Xuan Lin,1,2 Yu Chen,1,2
Yu-Feng Wang,1,2 Chang-Jian Zhou,1,2 Ping-Gang Peng,1,2 Li-Gang Wang,1,2 Li-Tian
Liu1,2
1. Institute of Microelectronics, Tsinghua University, Beijing 100084, China
2.Tsinghua National Laboratory for Information Science and Technology (TNList),
Tsinghua University, Beijing 100084, China
This file includes:
SUPPLEMENTARY METHOD
FIG. S1
SUPPLEMENTARY DISCUSSION
a)
Author to whom correspondence should be addressed. Electronic mail: RenTL@tsinghua.edu.cn.
SUPPLEMENTARY METHODS
We used the silver nanowires (AgNWs) suspension 100 mg/m2 in alcohol (XF NANO,
Inc.) as the original materials. The commercial anodic aluminum oxide (AAO) member
(Whatman, Inc.) was use to filter AgNWs suspension to obtain uniform film of nanowires
(Figure 1(a)). A polydimethylsiloxane (PDMS) stamp was brought into contact with the
AAO membrane and the AgNWs film was picked up on the stamp (Figure 1(b)). The
PDMS stamp adhereing the nanowires was pressed on the receiving substrate
(Polyethylene Terepthalate/Glass) at 100 ℃ temperature (Figure 1(c)). The PDMS stamp
was peeled off slowly from the substrate and the AgNWs was left on the substrate after a
few minutes (Figure 1(d)). Then the electrode was adhered to the both sides of AgNWs
(Figure 1(e)). After anealing the nanowire film at 200 ℃ for 20 minutes, the AgNWs’
performance of 15 ohms at 85% transmittance could be achieved.
SUPPLEMENTARY FIGURES AND CAPTIONS
FIG S1. Theoretical sound directivity of the AgNWs-SED at (a) 10 kHz sound frequency,
(b) 16 kHz sound frequency, (c) 20 kHz sound frequency, (d) 30 kHz sound frequency, (e)
40 kHz sound frequency, (f) 50 kHz sound frequency.
SUPPLEMENTARY DISCUSSIONS
Considering the AgNWs sound-emitting devices (AgNWs-SEDs) as a point sound
source in far-field, the theoretical half-space directivity D( ,  ) can be written as
following:
D( ,  )  sin c(
kL
k0 Lx
sin  cos  )sin c( 0 y sin  sin  )
2
2
(1)
Where the  and  are the angles of a spherical coordinate system. k0  2 / 0 is
the isentropic wave-number. The AgNWs-SED places in the origin of the coordinate
system. Lx and L y are sound source length and width, respectively.
Fig. S1 shows the sound radiation of AgNWs-SED in far-field. The on-axis direction
has the largest sound intensity which decreases with the angle. It can be explained by the
sound interference. When sound frequency is 10 kHz, the main intensity area focuses on
axis ±20 angles as shown in fig. S1(a). Under 16 kHz, the main intensity area focuses on
axis ±10 angles as shown in fig. S1(b). The same results are obtained when the frequency is
20, 30, 40 and 50 KHz respectively as shown in Fig. S1(c)~(f). It is noticed that the main
intensity area decreases with the increase of the sound frequency. As the wavelength
decreases with the increase of the sound frequency, the sound interference will happen in
smaller angle. This is the reason leading to the main intensity area decrease with the
frequency.