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Abstract Electron transfer is a fundamental process in chemistry, biology, and physics. One of the most intriguing questions concerns the realization of the transitions between nonadiabatic and adiabatic regimes of electron transfer. Using colloidal quantum dot molecules, we computationally demonstrate how the hybridization energy (electronic coupling) can be tuned by changing the neck dimensions and/or the quantum dot sizes. This provides a handle to tune the electron transfer from the incoherent nonadiabatic regime to the coherent adiabatic regime in a single system. We develop an atomistic model to account for several states and couplings to the lattice vibrations and utilize the mean-field mixed quantum-classical method to describe the charge transfer dynamics. Here, we show that charge transfer rates increase by several orders of magnitude as the system is driven to the coherent, adiabatic limit, even at elevated temperatures, and delineate the inter-dot and torsional acoustic modes that couple most strongly to the charge transfer dynamics.
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Excited state dynamics in a sodium and iodine co-doped lead telluride nanowire
Materials that convert wasted heat into electricity are needed to help solve global warming and other climate challenges. Thermoelectric nanowires are novel metamaterials for such applications. Non-adiabatic coupling computations are critical in understanding thermally activated charge transfer in thermoelectric materials. Here, non-adiabatic computations are used to evaluate electron relaxation rates in lead telluride nanowires. This work reports results on PbTe (lead telluride) atomistic models doped with sodium and iodine that contain 288 atoms in simulation cells with periodic boundary conditions. The calculations are performed on the basis of ground-state DFT under the VASP software. The transitions between states are modelled in terms of Redfield equation of motion parameterised by on-the-fly non-adiabatic couplings along thermalised molecular dynamic trajectory. The initial states are approximated by the promotion of an electron from occupied to unoccupied Kohn–Sham orbital. In each transition, the change of the energy and spatial charge distribution with respect to time were calculated, demonstrating formation of charge transfer. The trends of electron and hole relaxation rates comply with the energy gap law.
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- PAR ID:
- 10258131
- Date Published:
- Journal Name:
- Molecular Physics
- ISSN:
- 0026-8976
- Page Range / eLocation ID:
- e1874557
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1080/00268976.2021.1874557
