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Prashant V. Kamat, J. Am. Chem. Soc. 2007, 129: 41ห้องสมุดไป่ตู้6–4137.
Linking CdSe QDs to TiO2 Surface with a Bifunctional Surface Modifier
Prashant V. Kamat. J. Phys. Chem. CSOC. , 2008, 112 (48): Prashant V. Kamat. J. AM. CHEM. 2006, 128: 18737-18753. 2385-2393.
2
Structure of CdSe Quantum Dots
Wurtzite
Zinc blende
Rock salt
戴全钦. 吉林大学博士学位论文，2007
3
Cd(CH3)2 + TOPSe + TOPO
Solution A: Cd(CH3)2 + TOP
Combining
CdSe/TOPO
Solution B: Se + TOP
8
CdAc2 + Na2SeSO3
Green Methods
CdAc2· H2O
By stiring
CdSe
Se S
O
O
NaOH
Dissolving
O
C2H5OH+H2O
By stiring
Autoclave (40-150℃)
OA
Na2SeSO3
Nucleation
9
Y.D. Li. Inorganic Chemistry. 2008, 47(11): 5022-5028.
Quantum Dot Solar Cell
② Semiconductor nanostructure polymer solar cell
③ Quantum dot sensitized solar cell
④ Metal-semiconductor photovoltaic cell
A. J. Nozik. Physica E, 2002 (14): 115-200.
Drug Screening
Biological probe
12
―The emergence of semiconductor nanocrystals as the building blocks of nanotechnology has opened up new ways to utilize them in next generation solar cells.‖
6
CdO + Se/ODE + ODE = CdSe
CdO
Dissolving
OA+ODE
Heating
Injecting
Se+ODE
Mixture (300℃)
Cooling
Nucleation
X.G. Peng, et al. Angewandte Chemie-International Edition, 2002, 41(13): 7 2368-2371.
Injecting
Solvent: TOPO (300℃)
Cooling
Prevent further nucleation
Nucleation
4 MIT M.G. Bawendi, et al. J. Am. Chem. Soc. 1993, 115 (19): 8706-8715.
Room temperature optical absorption spectra of CdSe nanocrystallites dispersed in hexane and ranging in size from ~1.2 nm to 11.5 nm.
Photoluminescence
Q. J. Sun, et al. Nature Photonics. 2007,1, 717.
11
LED
Solar cell
Laser devices
Applications of Quantum Dots
Medical Imaging Biological Labeling Biochip
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Prashant V. Kamat. J. Phys. Chem. C, 2008, 112 (48): 18737-18753.
Quantum dot sensitized solar cell—QDSSC
Left: The dependence of electron transfer rate constant on the energy difference between the conduction bands. Right: Scheme illustrating the principle of electron transfer from two different size CdSe quantum dots into TiO2 nanoparticle.
1240 Eg (eV ) (nm)
D (2.6786 109 )λ 4 (4.9348 106 )λ 3 (3.4222 103 )λ 2 1.0511 λ 121.74
M.G. Bawendi, et al. J. Am. Chem. Soc. 1993, 115 (19): 8706-8715.
Prashant V. Kamat. J. Phys. Chem. C, 2008, 112 (48): 18737-18753.
Artistic impression of a rainbow solar cell assembled with
different size CdSe quantum dots on TiO2 nanotube array.
Fluorescence of the CdSe with different emission (λex ) 365nm
Y.D. Li, et al. Inorganic Chemistry. 2008, 47(11): 5022-5028.
10
Core–shell structures
TEM
14
Schematic diagram showing the strategies to develop quantum dot (semiconductor nanocrystal) based solar cells: (a) metal-semiconductor junction (b) polymer-semiconductor (c) semiconductor-semiconductor systems
5
CdO + TOPSe + TOPO + TDPA
CdO
Dissolving
CdSe
TDPA+TOPO (300-320℃)
Cooling
Injecting
Se + TOP
Solution (270℃)
Cooling
Nucleation
X.G. Peng, et al. J. Am. Chem. Soc, 2001. 123(1): 183-184.
Prashant V. Kamat. J. Phys. Chem. C, 2008, 112 (48): 18737-18753.
Left: Photocurrent response as a function of the amount of TiO2 deposited on carbon fiber electrode (CFE)； Right: Scheme showing the electron transport through SWCNT and SEM image of the SWCNT-TiO2 composite.
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Prashant V. Kamat. J. Phys. Chem. C, 2008, 112 (48): 18737-18753.
Quantum dot sensitized solar cell—QDSSC
Nitrogen doped
Principle of operation of quantum dot sensitized solar cell
19
a
b
Bifunctional organic molecule
I-V characteristics of (a) OTE/TiO2 and (b) OTE/TiO2/MPA/CdSe films. Electrolyte 0.1 M Na2S. Fast capture of electrons at the quantum dot interface remains a major challenge for efficient harvesting of light energy.
Prashant V. Kamat. J. AM. CHEM. SOC. 2006, 128: 2385-2393.
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Emerging Strategies to Capture and Transport Photogenerated Electrons
Photocurrent generation using CdSe-nC60 composite clusters IPCE：Incident Photon to Current-generation Efficiency
Lopez-Luke, T. J. Phys. Chem. C. 2008, 112:1282–1292.
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