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Modulating electronic coupling at the quantum dot/molecule interface by wavefunction engineering
DOI:10.1063/1.5083056.png)
摘要
En 中文
In this work, we use wavefunction engineering by varying the size of Quantum Dots (QDs) and tuning the delocalization (or diffuseness) of frontier orbitals of an acceptor molecule to modulate charge transfer dynamics at the QD/molecule interface. For this purpose, we apply our recently developed bulk-adjusted linear combination of atomic orbitals (BA-LCAO) approach for nanostructures and a density functional theory (DFT) for the acceptor molecules. These electronic structure calculations, combined with extensive molecular dynamics simulations using a fragmented molecular mechanics (FraMM) force field, reveal intimate details of charge transfer across the QD/Acceptor interface. For the spherical wurtzite-(CdSe)(201) and (CdSe)(693) nanostructures, as model QDs with respective 2.8 and 4.1 nm diameters, and anthraquinone-2,3-dicarboxylic acid and its derivatives with the 7-OH, 7-OF, 10-BH, and 10-CH2 substituents, as model molecular acceptors, we find that (1) both the electron donating and withdrawing groups greatly enhance hole transfer by means of diffusing the acceptor HOMO; (2) electron transfer is affected only by the electron donating groups; (3) solvent effects are largely negligible for the orbital overlaps, and (4) consistent with spatial confinement theories, the electron density of the smaller QD penetrates farther into the vacuum than the corresponding density of the larger QD leading to stronger coupling with the acceptor. These findings suggest that (a) one can effectively control charge transfer across the QD/molecule interface by either changing the size of the QD or by tuning diffuseness of frontier orbitals of the acceptor molecule and (b) the combination of the recently developed BA-LCAO approach for QDs with a DFT for the acceptor molecules, facilitated by the use of the FraMM force field and extensive molecular dynamics simulations, provide qualitatively accurate description of charge transfer dynamics at the QD/acceptor interface. Published under license by AIP Publishing.
Keyword:
ATOMIC SCREENING CONSTANTS
TOTAL-ENERGY METHOD
MOLECULAR-MECHANICS
CHARGE SEPARATION
NANOCRYSTALS
LIGHT
DOTS
TRANSITION
DYNAMICS
FORCE
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期刊
IF:
3.1
论文数:
7.2W
被引数:
23.2W
机构
引用论文
Role of Solvent Dielectric Properties on Charge Transfer from PbS Nanocrystals Molecules溶剂介电性质对PbS纳米晶分子电荷转移的作用
NANO LETTERS
IF9.1

