Size Dependent Optical Properties of Luminescent Zn3P2 Quantum Dots
Size Dependent Optical Properties of Luminescent Zn3P2 Quantum Dots Minh Q. Ho, Richard J. Alan Esteves, Gotluru Kedarnath, Indika U. Arachchige* Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284–2006, United States
Supplementary Information
S1
Intensity (arb. unit) 20
30
40
50
2θ (Degrees) Figure S1. Powder X-ray diffraction pattern of the larger (~50–60 nm) Zn3P2 crystallites produce in ODE at 300 °C for 30 min. ICCD–PDF overlay of tetragonal Zn3P2 (JCPDS 01–073– 4212) is shown as vertical black lines.
S2
Absorption (α/s)
1.53 eV 1.0
1.5
2.0
2.5
3.0
3.5
Energy (eV) Figure S2. A representative solid state absorption spectrum of the larger (~50–60 nm) Zn3P2 crystallites produced in ODE at 300 °C for 30 min. Data acquired in the reflectance mode were converted to absorption using Kubelka-Munk remission function.
S3
Intensity (arb. unit) 20
30
40
50
2θ (Degrees) Figure S3. PXRD pattern of the product when a pre-mixed solution of (TMSi)3P/Et2Zn/ODE was injected in HDA at 300 °C and grown for 60 min. ICCD–PDF overlay of tetragonal Zn3P2 (JCPDS 01–073–4212) is shown as vertical black lines.
S4
Figure S4. A representative SEM/EDS spectrum of the Zn3P2 NCs prepared in HDA/ODE at 300 °C for 60 min.
S5
Intensity (arb. unit)
b a 20
30
40
50
2θ (Degrees) Figure S5. PXRD patterns of the (a) Zn3P2 NCs prepared at 300 °C for 60 min. along with the (b) post–TGA annealed residue of the sample. The ICCD-PDF overlay of Zn3P2 tetragonal (PDF# 01–073–4212) and hexagonal Zn (PDF# 00–004–0831) are shown as vertical black and red lines, respectively.
S6
Figure S6. Representative TEM images of Zn3P2 NCs prepared in HDA/ODE at 300 °C for (A) 15 min, (B) 30 min, (C) 45 min, (D) 60 min, and (E) 90 min. The last image in C shows the high resolution TEM image of a single Zn3P2 NC prepared at 300 °C for 45 min. S7
Absorbance
e d c b a 400
600
800
1000
Wavelength (nm) Figure S7. Solution absorption spectra of Zn3P2 NCs prepared in HDA/ODE at 300 °C for (a) 15, (b) 30, (c) 45, (d) 60, and (e) 90 min.
S8
Absorption (α/s)
[A]
e d c b a 1.0
1.5
2.0
2.5
3.0
3.5
4.0
Energy (eV)
Absorption (α/s)
[B]
d c b a 1.0
1.5
2.0
2.5
3.0
3.5
4.0
Energy (eV) Figure S8. Solid–state diffuse reflectance spectra (converted to absorption using Kubelka–Munk function) of [A] Zn3P2 NCs synthesized in HDA/ODE at 300 °C for (a) 15, (b) 30, (c) 45, (d) 60, and (e) 90 min. and [B] Zn3P2 NCs produced in HDA/ODE at (a) 230 °C, (b) 250 °C, (c) 275 °C, and (d) 300 °C for 1 h.
S9
Intensity (arb. unit)
Intensity (arb. unit)
300 nm 340 nm 380 nm 420 nm
400
500
600
700
Wavelength (nm)
Zn3P2 NCs HDA/ODE
400
500
600
700
800
900
1000
Wavelength (nm) Figure S9. Emission spectrum of Zn3P2 NCs produced in HDA/ODE at 300 °C for 90 min along with the emission spectra of pure HDA/ODE mixture excited at different wavelengths (300-420 nm). The HDA/ODE mixture was heated at 300 °C for 3 h under Ar flow prior to analysis. Inset shows the magnified emission plots of pure HAD/ODE mixture.
S10
PL Intensity (arb. unit)
481 nm
Intensity (arb. unit)
[A]
400
500
600
[C]
(-t/τ1)
l(t) = A*e
τ1 = 2.96 ± 0.13 ns τ2 = 20.76 ± 7.01 ns
10
700
20
535 nm
PL Intensity (arb. unit) 500
40
50
60
70
[D]
Intensity (arb. unit) 400
30
Time (ns)
Wavelength (nm)
[B]
(-t/τ2)
+ B*e
600
l(t) = A*e τ1 = 0.60 τ2 = 4.66
0
700
5
10
(-t/τ1)
+ B*e
(-t/τ2)
± 0.02 ns ± 0.42 ns
15
20
Time (ns)
Wavelength (nm)
Figure S10. Emission spectra of Zn3P2 NCs produced in HDA/ODE at 300 °C for [A] 15 min. and [B] 60 min. along with time-resolved photoluminescence plots of corresponding emission: [C] 481 nm and [D] 535 nm.
S11
Supplementary Information
S1
Intensity (arb. unit) 20
30
40
50
2θ (Degrees) Figure S1. Powder X-ray diffraction pattern of the larger (~50–60 nm) Zn3P2 crystallites produce in ODE at 300 °C for 30 min. ICCD–PDF overlay of tetragonal Zn3P2 (JCPDS 01–073– 4212) is shown as vertical black lines.
S2
Absorption (α/s)
1.53 eV 1.0
1.5
2.0
2.5
3.0
3.5
Energy (eV) Figure S2. A representative solid state absorption spectrum of the larger (~50–60 nm) Zn3P2 crystallites produced in ODE at 300 °C for 30 min. Data acquired in the reflectance mode were converted to absorption using Kubelka-Munk remission function.
S3
Intensity (arb. unit) 20
30
40
50
2θ (Degrees) Figure S3. PXRD pattern of the product when a pre-mixed solution of (TMSi)3P/Et2Zn/ODE was injected in HDA at 300 °C and grown for 60 min. ICCD–PDF overlay of tetragonal Zn3P2 (JCPDS 01–073–4212) is shown as vertical black lines.
S4
Figure S4. A representative SEM/EDS spectrum of the Zn3P2 NCs prepared in HDA/ODE at 300 °C for 60 min.
S5
Intensity (arb. unit)
b a 20
30
40
50
2θ (Degrees) Figure S5. PXRD patterns of the (a) Zn3P2 NCs prepared at 300 °C for 60 min. along with the (b) post–TGA annealed residue of the sample. The ICCD-PDF overlay of Zn3P2 tetragonal (PDF# 01–073–4212) and hexagonal Zn (PDF# 00–004–0831) are shown as vertical black and red lines, respectively.
S6
Figure S6. Representative TEM images of Zn3P2 NCs prepared in HDA/ODE at 300 °C for (A) 15 min, (B) 30 min, (C) 45 min, (D) 60 min, and (E) 90 min. The last image in C shows the high resolution TEM image of a single Zn3P2 NC prepared at 300 °C for 45 min. S7
Absorbance
e d c b a 400
600
800
1000
Wavelength (nm) Figure S7. Solution absorption spectra of Zn3P2 NCs prepared in HDA/ODE at 300 °C for (a) 15, (b) 30, (c) 45, (d) 60, and (e) 90 min.
S8
Absorption (α/s)
[A]
e d c b a 1.0
1.5
2.0
2.5
3.0
3.5
4.0
Energy (eV)
Absorption (α/s)
[B]
d c b a 1.0
1.5
2.0
2.5
3.0
3.5
4.0
Energy (eV) Figure S8. Solid–state diffuse reflectance spectra (converted to absorption using Kubelka–Munk function) of [A] Zn3P2 NCs synthesized in HDA/ODE at 300 °C for (a) 15, (b) 30, (c) 45, (d) 60, and (e) 90 min. and [B] Zn3P2 NCs produced in HDA/ODE at (a) 230 °C, (b) 250 °C, (c) 275 °C, and (d) 300 °C for 1 h.
S9
Intensity (arb. unit)
Intensity (arb. unit)
300 nm 340 nm 380 nm 420 nm
400
500
600
700
Wavelength (nm)
Zn3P2 NCs HDA/ODE
400
500
600
700
800
900
1000
Wavelength (nm) Figure S9. Emission spectrum of Zn3P2 NCs produced in HDA/ODE at 300 °C for 90 min along with the emission spectra of pure HDA/ODE mixture excited at different wavelengths (300-420 nm). The HDA/ODE mixture was heated at 300 °C for 3 h under Ar flow prior to analysis. Inset shows the magnified emission plots of pure HAD/ODE mixture.
S10
PL Intensity (arb. unit)
481 nm
Intensity (arb. unit)
[A]
400
500
600
[C]
(-t/τ1)
l(t) = A*e
τ1 = 2.96 ± 0.13 ns τ2 = 20.76 ± 7.01 ns
10
700
20
535 nm
PL Intensity (arb. unit) 500
40
50
60
70
[D]
Intensity (arb. unit) 400
30
Time (ns)
Wavelength (nm)
[B]
(-t/τ2)
+ B*e
600
l(t) = A*e τ1 = 0.60 τ2 = 4.66
0
700
5
10
(-t/τ1)
+ B*e
(-t/τ2)
± 0.02 ns ± 0.42 ns
15
20
Time (ns)
Wavelength (nm)
Figure S10. Emission spectra of Zn3P2 NCs produced in HDA/ODE at 300 °C for [A] 15 min. and [B] 60 min. along with time-resolved photoluminescence plots of corresponding emission: [C] 481 nm and [D] 535 nm.
S11
