Highly Efficient Cadmium-Free Quantum Dot Light Emitting Diodes ...
Supporting Information
Highly Efficient Cadmium-Free Quantum Dot Light Emitting Diodes Enabled by the Direct Formation of Excitons within InP@ZnSeS Quantum Dots
Jaehoon Lim, Myeongjin Park, Wan Ki Bae, Donggu Lee, Seonghoon Lee,* Changhee Lee,* and Kookheon Char*
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Figures
Figure S1. (a) High binding energy cut-off region and (b) valence band region (right) in UPS of InP@ZnSeS QDs with 1.1 nm (red) and 1.7 nm (green) shell thickness.
Figure S2. AFM height images and water contact angles (inset) of ZnO/PFN thin films prepared with (a) 0; (b) 0.5; (c) 1.0; and (d) 1.5 mg mL-1 of PFN concentration (scale bar: 500 nm).
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Figure S3. (a) A current density (J) – voltage (V) – luminance (L) characteristic, (b) an EQE-J curve, and (c) EL spectra of QLEDs based on InP@ZnSeS QDs with 1.1 nm of shell thickness at different current densities.
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Tables Table S1. Atomic contents of InP@ZnSeS QDs Shell Thickness (nm) Component (%)
0 (core, before adding SeTOP)
0.6 (adjacent to InP core)
1.1
1.7
In
56 ± 1.0
7.5 ± 1.5
2.4 ± 0.7
1.7 ± 0.7
P
35 ± 2.7
11 ± 0.9
4.0 ± 0.3
5.9 ± 1.0
Zn
3.5 ± 0.7
60 ± 1.7
46 ± 0.3
42 ± 4.1
Se
0
12 ± 2.5
5.8 ± 1.6
2.6 ± 0.9
S
4.8 ± 1.2
9.3 ± 2.5
42 ± 3.7
45 ± 0.5
Table S2. Valence band maximum (VBM), conduction band minimum (CBM), and bandgap (Eg) of InP@ZnSeS QDs Shell Thickness (nm)
VBM (eV)
CBM (eV)
Eg (eV)
1.1
5.90
3.52
2.38
1.7
5.93
3.54
2.39
Table S3. A summary of root-mean-square roughnesses and thicknesses of ZnO/PFN thin films given in Figure S2 Concentration of PFN solution (mg mL-1)
RMS roughness (nm)
Thickness (nm)
0
1.5
45.2
0.5
1.6
43.1
1.0
2.4
44.5
1.5
1.3
47.5
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Highly Efficient Cadmium-Free Quantum Dot Light Emitting Diodes Enabled by the Direct Formation of Excitons within InP@ZnSeS Quantum Dots
Jaehoon Lim, Myeongjin Park, Wan Ki Bae, Donggu Lee, Seonghoon Lee,* Changhee Lee,* and Kookheon Char*
1
Figures
Figure S1. (a) High binding energy cut-off region and (b) valence band region (right) in UPS of InP@ZnSeS QDs with 1.1 nm (red) and 1.7 nm (green) shell thickness.
Figure S2. AFM height images and water contact angles (inset) of ZnO/PFN thin films prepared with (a) 0; (b) 0.5; (c) 1.0; and (d) 1.5 mg mL-1 of PFN concentration (scale bar: 500 nm).
2
Figure S3. (a) A current density (J) – voltage (V) – luminance (L) characteristic, (b) an EQE-J curve, and (c) EL spectra of QLEDs based on InP@ZnSeS QDs with 1.1 nm of shell thickness at different current densities.
3
Tables Table S1. Atomic contents of InP@ZnSeS QDs Shell Thickness (nm) Component (%)
0 (core, before adding SeTOP)
0.6 (adjacent to InP core)
1.1
1.7
In
56 ± 1.0
7.5 ± 1.5
2.4 ± 0.7
1.7 ± 0.7
P
35 ± 2.7
11 ± 0.9
4.0 ± 0.3
5.9 ± 1.0
Zn
3.5 ± 0.7
60 ± 1.7
46 ± 0.3
42 ± 4.1
Se
0
12 ± 2.5
5.8 ± 1.6
2.6 ± 0.9
S
4.8 ± 1.2
9.3 ± 2.5
42 ± 3.7
45 ± 0.5
Table S2. Valence band maximum (VBM), conduction band minimum (CBM), and bandgap (Eg) of InP@ZnSeS QDs Shell Thickness (nm)
VBM (eV)
CBM (eV)
Eg (eV)
1.1
5.90
3.52
2.38
1.7
5.93
3.54
2.39
Table S3. A summary of root-mean-square roughnesses and thicknesses of ZnO/PFN thin films given in Figure S2 Concentration of PFN solution (mg mL-1)
RMS roughness (nm)
Thickness (nm)
0
1.5
45.2
0.5
1.6
43.1
1.0
2.4
44.5
1.5
1.3
47.5
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