Temperature effects on the growth of SnS nanosheet structure using
thermal decomposition
Bo-Jia Huang, Jyun-Jia Huang, Sheng-Chang Wang*
Department of Mechanical Engineering, Southern Taiwan University
Tainan, TAIWAN
*E-mail: scwang@mail.stut.edu.tw
指導教授：王聖璋 博士(Pro.S-C Wang)
學生:黃伯嘉(Bo-Jia Huang)
2016/3/23
Outline
-Abstract
-Introduction
-Experimental
-Results and Discussion
-Conclusion
2
Abstract
Abstract
In this research, Tin sulfide (SnS) nanostructure were synthesized in
oleylamine solution using thermal decomposition method. The sulfur and tin
oleate were used as the S and Sn sources, respectively. Various
decomposition temperature, were conducted to growth the SnS powders in Ar
for 10-60 min. The morphology, electrical and optical properties of SnS film
was characterized by SEM,TEM, XRD and UV-Vis.
4
Introduction
Introduction
SnS is a narrow band gap IV-VI semiconductor, which are
optically active in the near-infrared and infrared. SnS band gad between
that of Si (1.12 eV) and GaAs (1.43 eV) [1].
It has a high absorption coefficient (α>104 cm−1),and has absorbs
the solar spectrum best to be able the crack value (~1.3 eV) [2].The theory
electro-optic transfer efficiency can reaches as high as above 25%[3]
In the past decades, these semiconductor attract great interest for
their application in photovoltaics, near-infrared detectors and biomedical
application.
6
Experimental
Experimental
In this study, chemical oleic acid, (OA , 90%, SHOWA, Japan), and
commercial SnO powder (Riedel-de Haen, Germany) were used to form the
tin oleate complex, and S powder dissolve in Oleylamine (OLA , 90%,
ACROS), were used as the coordinating solvent and a phase transformation
controller reagent. The detail synthesis procedure and characterization were
shown in Fig. 1.
SnO 1 mmol
OA 3 mmol
Heat to 310°C for 60 min and stir in
Argon
S
0.07 g
OLA
6-18 ml
Sn(OA)X
0.08 g
Heat to 220~310˚C for 10~60 min
and stir in Argon
5 ml Hexane and 15 ml ethanol
centrifugation 5000 rpm with 30 min
5 ml Hexane and 15 ml ethanol
contrifugation 5000 rpm with 30 min
drying 100˚C with 20 min
drying 100°C with 20 min
Sn(OA)2
SnS
SEM
TEM
fig1. Flow chart of experimental procedure.
XRD
8
Results and Discussion
Results and Discussion
X-ray diffraction patterns obtained for SnS powder synthesized at different
deposition potential are shown in Fig .2 a-b. All peaks in Fig.2a-b can be
indexed to these of the orthorhombic SnS.the relative intensity of the peaks
corresponding to the strongest peak(040)planes to that of (111) planes varies
significantly from the reported values.
Fig. 2 XRD patterns of SnS powder at various potentials : (a)at 220°C
(b)at 280°C
Results and Discussion
The morphology of the SnS powder synthesized at 280°C was studied
by SEM and TEM, which are shown in Fig. 3 (a) and (b). The shape of the
SnS sample is flower-like composed by several sheet structures, which is
observed by TEM image. The diffraction pattern of the irregular sheet
structure is confirmed as the single crystal SnS phase, as shown in fig. 3
(c).
Fig 3 Decomposition temperature at 220°C SnS crystal structure image.
(a) SnS SEM (b)SnS TEM (c) SAED pattern
Results and Discussion
As the synthesis temperature increase to 280°C, the SnS
morphology is changed to regular square sheet, as shown in SEM
image of Fig. 4(a). The TEM image is further confirmed that the
morphology of SnS is a squared sheet with rounded-corner. The TEM
image shows uniformed contrast with some bending contour fringes in
the nanosheet, which identify the sheet is 1 min edge length with very
thin and uniform in thickness.
Compared the TEM image and it corresponding diffraction pattern,
we can conclude the that the edge direction of the nanosheet is <101>
and the sheet plane is (010).
Fig 4 Decomposition temperature at 280°C SnS crystal structure image.
(a)SnS SEM (b)SnS TEM (c) SAED pattern
Results and Discussion
The representative optical absorption spectrum of the two kinds of SnS
structures is shown in Fig. 5. This figure indicated that the both SnS structures
have high absorption in the range of ultraviolet. The nanosheet SnS structure
has a higher absorption than the flower-like SnS.
Fig 5 SnS film on ITO glass absorption spectrum(A)
flower like (B) sheet structure
Conclusion
Conclusion
The two-dimensional SnS crystal were synthesized by hydrothermal
decomposition using Sn(OA)2 and S powder as sources in OLA solovent. The
results show that a flower-like SnS structure composed of several irregular
flakes is synthesized at 220°C. A squared SnS nanosheet with rounded-corner
structure is synthesize by 280°C. The nanosheet SnS structure has a higher
absorption than the flower-like SnS
15
Thanks for your attention