the performance of these samples in el devices. the
TRANSCRIPT
Synthesis, Characterization, and
Applications of Cadmium-free Light-
emitting Semiconducting Quantum Dots
Po-Hsiang Chuang (莊博翔) and Ru-Shi Liu* (劉如熹)
Department of Chemistry, National Taiwan University, Taipei 106, Taiwan Abstract
The first part, CIS I-III-VI-type QDs were synthesized under different growth times via facile solvothermal method. The core CIS was effectively passivated by the coating
layer of ZnS, increasing the QYs and causing a blueshift of the emission band. Red-emitting CIS/ZnS QDs that were blended with Y3Al5O12:Ce3+ phosphor-based white
LEDs were also fabricated. The CRI of white LEDs was improved. These results clearly showed that CIS/ZnS QDs are promising candidates for white LED application.
In the second part, synthesis and optoelectronic application of CIS/ZnS core/shell QDs with varied [Cu]/[In] ratio are presented. CIS/ZnS QDs can be tuned from 550 nm to
618 nm by controlling [Cu]/[In] ratio. QDs combined green light phosphors with blue LEDs, are fabricated to obtain white LEDs with high CRI values. We also examined
the performance of these samples in EL devices. The initial results demonstrated the potential of CuInS2/ZnS QDs as alternative materials for light-emitting applications.
In the third part, we also synthesized the fluorescence of dental resins containing InP QDs as luminophores. The core/shell QDs that were obtained through stepwise
solvothermal ZnS shell coating conditions with improvemently fluorescent. The fluorescence peak of dental resin composites can be tailored by incorporating InP QDs.
Employing InP QDs in the creation of dental resin composites allows for the fabrication of restorative materials with biocompatible fluorescence properties.
Topic I CuInS2 Size Tuning CuInS2 Composition Tuning InP Size Tuning
Topic II Topic III
400 500 600 700 800
Ab
s /
norm
ali
zed
(a.u
)
Wavelength (nm)
CIS 6h
CIS 8h
400 500 600 700 800
Ab
s /
no
rma
lize
d(a
.u)
Wavelength (nm)
CIS/ ZnS 6h
CIS/ ZnS 8h
A8hA6hA8hZnSA6hZnS
QDs QY (6 h) QY (8 h)
CIS 1.2% 3.4%
CIS/ZnS 48% 83%
ECB
EVB
CuInS2
ZnSCuZnInS2
Alloying
ACISZnS
30 40 50 60 70
CIS
CIS 8h
(112) (204)(220)
(116)(312)
(111) (220) (311)
CIS/ZnS 8h
CIS 6h
CIS/ZnS 6h
Inte
nsi
ty (
a.u
.)
2 (degree)
ZnS
LEDs type CRI Efficiency (lm/W)
YAG 75 76.7
YAG+Red QDs 86 43.7
400 500 600 700 800
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
El
Inte
nsi
ty (
a.u
.)
Wavelength (nm)
20mA
40mA
60mA
80mA
100mA
120mA
20 40 60 80 100 120
20
30
40
50
Forward Current (mA)
Lu
min
ou
s E
ffic
ien
cy (
lm/W
)
84.5
85.0
85.5
86.0
86.5
87.0 Luminous Efficiency
CRI
CR
I
20 40 60 80 100 120
85.6
85.8
86.0
86.2
86.4
86.6
86.8
CC
T(K
)
Forward Current (mA)
CRI
CCT
6000
7000
8000
9000
10000
11000
12000
13000
CR
I
A
B
X
Y
QDs assisted B: (0.3370, 0.3073)
YAGA: (0.3001, 0.3163)
300 400 500 600 700 800
CIS 1/1
CIS 1/2
CIS 1/4
CIS 1/6
Abs
orba
nce
(a.u
.)
Wavelength (nm)
600 650 700 750 800
CIS 1/1
CIS 1/2
CIS 1/4
CIS 1/6
PL In
tens
ity (a
.u.)
Wavelength (nm)
300 400 500 600 700 800
Abs
orba
nce
(a.u
.) CIS/ZnS 1/1
CIS/ZnS 1/2
CIS/ZnS 1/4
CIS/ZnS 1/6
Wavelength (nm)
500 550 600 650 700 750 800
CIS/ZNS 1/1
CIS/ZNS 1/2
CIS/ZNS 1/4
CIS/ZNS 1/6
PL
Int
ensi
ty (a
.u.)
Wavelength (nm)
1.8
2.0
2.2
2.4
Ab
sorb
ance
Ban
g G
ap (
eV)
CIS
CIS/ZnS
1/61/41/1
[Cu]/[In] Ratio
1/2
1.8
2.0
2.2
Em
issi
on B
ang
Gap
(eV
)
CIS
CIS/ZnS
1/61/41/1
[Cu]/[In] Ratio
1/2
Cu:In Position FWHM Q.Y
1/1 669 nm 112 2.8%
1/2 663 nm 110 3.2%
1/4 660 nm 108 5.6%
1/6 654 nm 111 2.4%
Cu:In Emission FWHM Q.Y
1/1 618 nm 120 53%
1/2 598 nm 115 62%
1/4 582 nm 117 81%
1/6 558 nm 112 44%
CIS CIS/ZnS
CuInS2 Quantum Dot
VS
VCu
InCu
CuInS2
Bulk
VS
InCu
VCu
ECB
EVB
1S(h)
1S(e)
Bang gap
1.53 eV
CuInS2 /ZnSQuantum Dot
CISZnSCIS
PL pathway of CIS and CIS/ZnS
Donor−Acceptor pair (DAP)
30 40 50 60
2 (degree)
CuInS2
CIS 1/1
(112) (200) (204) (220) (116) (312)
CIS/ZnS 1/1
CIS 1/2
CIS/ZnS 1/2
CIS 1/4
CIS/ZnS 1/4
CIS 1/6
CIS/ZnS 1/6
Inte
nsity
(a.u
.)
ZnS
5 nm
Chalcopyrite strucutre
Phase data
Space group
I-42d
a 5.5240 Å
c 11.1050 Å
0.70
0.75
0.80
0.85
0.90
0.95
1.00
1.05
1.10
Tet
rago
nal D
isto
rtio
n
Emission position (nm)
669 663 660 654
0.235
0.236
0.237
0.238
0.239
0.240
Anion D
isplacement
[Cu]/[In] ratio
1/1 1/2 1/4 1/6
600 700 800
25oC
50oC
100oC
150oC
200oC
PL
In
ten
sity
(a
.u.)
Wavelength (nm)
600 650 700
PL
In
ten
sity
(a
.u.)
25oC
50oC
100oC
150oC
200oC
Wavelength (nm)
500 550 600 650 700
Wavelength (nm)
25oC
50oC
100oC
150oC
200oC
PL
In
ten
sity
(a
.u.)
500 550 600 650
PL
In
ten
sity
(a.u
.)
Wavelength (nm)
25oC
50oC
100oC
150oC
200oC
[Cu]/[In]=1/1 [Cu]/[In]=1/2
[Cu]/[In]=1/4 [Cu]/[In]=1/6
50 100 150 200
0
20
40
60
80
100
Rel
ati
ve
Inte
nsi
ty (
%)
Temperature (o
C)
CIS(1/1)/ZnS
CIS(1/2)/ZnS
CIS(1/4)/ZnS
CIS(1/6)/ZnS
[Cu]/[In]=1/1
[Cu]/[In]=1/2
[Cu]/[In]=1/4
[Cu]/[In]=1/6
CIE-X
CIE
-Y
(0.3163, 0.2988)
6552 K
20
40
60
80
100
120
RaR9R8R7R6R5R4R3R2
Color R
en
derin
g I
nd
ex
Munsell Code
Blue chip +Silicate
Blue chip +Silicate + CuInS2/ZnS
R1
32.7 lm/W
CRI: 89.9
h+
e-
Glass
ITO
HTL
ETL
Anode
Cathode
LiF/Al
EML
HIL
2.3 eV
5.2 eV
3.0 eV
5.7 eV
Alq3
Poly
TPD
3.1 eV
5.5 eV
5.0 eV
PEDOT
:PSS
2.5 eV
2.8 eV
4.7 eV
ITO
LiF/Al
QDs
En
erg
y (
eV
)
3.0 eV
4.0 eV
5.0 eV
6.0 eV
Alq3
Poly-TPD
PEDOT:PSS
Alq3 :Tris(8hydroxyquinolinato)aluminium
poly-TPD:poly[ N , N -bis(4-butylphenyl)- N , N -bis(phenyl)benzidine]
PEDOT:PSS: Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)
(0.448, 0.485)
450 500 550 600 650 700 750
0.0
0.2
0.4
0.6
0.8
1.0
In
ten
sity
(a.u
.)
Wavelength (nm)
EL
PL
8 10 12 14 16 18 20 22 24 26
0
200
400
600
800
1000
1200
Cu
rren
t D
en
sit
y (m
A/c
m2
)
Voltage (V)8 10 12 14 16 18 20 22 24 26
0
5
10
15
20
25
30
35
Voltage (V)
Lu
min
an
ce (
cd
/m2)
8 10 12 14 16 18 20 22 24 26
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
Voltage (V)
Cu
rren
t E
ffic
ien
cy (
cd
/A)
8 10 12 14 16 18 20 22 24 26
0.00
0.01
0.02
0.03
0.04
0.05
Voltage (V)
Po
wer E
ffic
ien
cy
(lm
/W)
400 500 600 700
0.0
0.2
0.4
Abs
orba
nce
/ Nor
mal
ized InP1
InP2
InP3
Wavelength (nm)
400 500 600 700 800
0.0
0.2
0.4
0.6
0.8
1.0 InP1
InP2
InP3
PL
Int
ensi
ty /
Nor
mal
ized
Wavelength (nm)
(a) (b)
InP1InP3 InP2
400 500 600 700
Abs
orba
nce
/ Nor
mal
ized #1 #6
#2 #7
#3 #8
#4 #9
#5
Wavelength (nm)
450 500 550 600 650 700 750
Wavelength (nm)
PL In
tens
ity/N
orm
aliz
ed
#1 (585nm)
#2 (573nm)
#3 (564nm)
#4 (560nm)
#5 (551nm)
#6 (540nm)
#7 (528nm)
#8 (518nm)
#9 (512nm)
510 520 530 540 550 560 570 580 59015
20
25
30
35
40
45
#9 #8#7
#6
#5
#4
#3
#2
#1 FWH
M (nm
)
PL q
uant
um y
ield
(%)
Wavelength (nm)
60
65
70
75
80
85
90
95
#9 #8 #7 #6 #5 #4 #3 #2 #1
400 500 600 700
Abso
rban
ce /
Norm
alize
d #1 #6
#2 #7
#3 #8
#4 #9
#5
Wavelength (nm)
450 500 550 600 650 700 750
Wavelength (nm)
PL In
tens
ity/N
orm
alize
d
#1 (585nm)
#2 (573nm)
#3 (564nm)
#4 (560nm)
#5 (551nm)
#6 (540nm)
#7 (528nm)
#8 (518nm)
#9 (512nm)
510 520 530 540 550 560 570 580 59015
20
25
30
35
40
45
#9 #8#7
#6
#5
#4
#3
#2
#1 FWH
M (nm
)
PL q
uant
um y
ield
(%)
Wavelength (nm)
60
65
70
75
80
85
90
95
#9 #8 #7 #6 #5 #4 #3 #2 #1
400 500 600 700
Abs
orba
nce
/ Nor
mal
ized #1 #6
#2 #7
#3 #8
#4 #9
#5
Wavelength (nm)
450 500 550 600 650 700 750
Wavelength (nm)
PL In
tens
ity/N
orm
aliz
ed
#1 (585nm)
#2 (573nm)
#3 (564nm)
#4 (560nm)
#5 (551nm)
#6 (540nm)
#7 (528nm)
#8 (518nm)
#9 (512nm)
510 520 530 540 550 560 570 580 59015
20
25
30
35
40
45
#9 #8#7
#6
#5
#4
#3
#2
#1
FWH
M (nm
)
PL q
uant
um y
ield
(%)
Wavelength (nm)
60
65
70
75
80
85
90
95
#9 #8 #7 #6 #5 #4 #3 #2 #1
Publications
20 30 40 50 60
(311)
(220)
(111)
(311)(220)
(111)
Inte
nsity
(a.u
.)
2 (degree)
InP
InP
InP/ZnS
ZnS
d111 = 3.39 A
Element Atomic%
In 17.6
P 27.0
Zn 13.8
S 41.6
A
A
A
A
Dental Resin
InP Quantum Dots
Biocompatible InP QDs/resin composite
400 450 500 550 600 650
0.0
5.0x106
1.0x107
1.5x107
2.0x107
2.5x107
PL
/ In
ten
sit
y(a
.u)
Wavelength (nm)
Z350
InP2-Z350
(b)
400 450 500 550 600
0.0
5.0x106
1.0x107
1.5x107
2.0x107
2.5x107
Wavelength (nm)
PL
/ In
ten
sit
y(a
.u)
Z350
InP3-Z350
0
20
40
60
80
100
120
Cell
Via
bil
lity
(%
)
120 h
Z350 InP2
InP2-Z350 Control
24 h 72 h
(a)
0
20
40
60
80
100
120 Z350 InP2
InP2-Z350 Control
Mea
n f
luo
resc
en
ce o
f D
CF
%
90 Min30 Min 60 Min
(b)
[1] Chuang, P.-H.; Lin, C. C.; Yang , H.; Liu, R.S. “Enhancing the Color Rendering
Index for Phosphor-converted White LEDs Using Cadmium-Free CuInS2/ZnS
QDs” J. Chin. Chem. Soc. 2013, 60, 801.
[2] Chuang, P.-H.; Lai, Y.-J.; Lin, C. C.; Wang, T-M. ; Yang, H.; LinL-D. ; Liu, R.S.
Facile dental resin composites with tunable fluorescence by tailoring a Cd-free
composition quantum dots. RSC Adv. 2013, 3,16639
[3] Chuang, P.-H.; Lin, C. C.; Liu, R.S. “Emission-tunable CuInS2/ZnS quantum
dots structure, optical properties, and application in white light-emitting diodes”
(Submitted to ACS Appl. Mater. Interfaces)
Papers
Patents 1].莊博翔, 劉如熹, 王子翔, 潘錫明, 一種發光元件, Illuminating assembly,中華民
國專利,申請號第 201403878號
[2].莊博翔, 賴彥蓉,劉如熹, 王子翔, 潘錫明, 擬合自然牙之牙科複合樹脂及其製
備方法, Dental composite resin fitting natural teeth and preparation method
thereof ,中華民國專利, 公開號第 201402158號
[3].莊博翔,林群哲,劉如熹, 葉宏立, 呂格維,一種高演色性之白光發光裝置, A
white light-emitting diodes with high color rendering index中華民國專利, 申
請中
[4].江德馨, 莊博翔, 葉巧雯, 劉如熹, 製造螢光粉之方法及該方法所製得之螢光
粉, Method for the preparation of phosphors and phosphors prepared therefrom,
中華民國專利, 公開號第 201226528號
[5].江德馨, 莊博翔, 葉巧雯, 劉如熹, 白光發光裝置, white light emitting device, 中
華民國專利, 公告號第 M408130號
II
I
III
Uv-Vis
PL and XRD
CIS/ZnS QDs-assisted white LEDs
EL spectra and luminous efficiency
Optical Properties of CIS and CIS/ZnS QDs
Optical Band and Emission Peak
XRD, TEM and Lattice Structure
Temperature PL QDs-assisted white LEDs
QD-LEDs L-I-V properties
Optical Properties of InP QDs
Optical Properties of InP/ZnS QDs
XRD of InP and InP/ZnS QDs
InP QDs-embedded resin Cytotoxicity assay