Exciton dissociation and charge separation at donor-acceptor interfaces from quantum-classical dynamics simulations

Area of Science:

• Organic Photovoltaics (OPV)
• Materials Science
• Physical Chemistry

Background:

• Exciton dissociation and charge separation are critical for OPV efficiency.
• Understanding these processes at donor-acceptor heterojunctions is key.

Purpose of the Study:

• To investigate the real-time dynamics of exciton dissociation and charge separation.
• To assess the accuracy and computational cost of the forward-backward trajectory solution (FBTS) method.
• To evaluate the impact of dimensionality on charge carrier generation.

Main Methods:

• Nonadiabatic dynamics simulations using the quantum-classical Liouville equation.
• Benchmark comparisons of low-dimensional donor-acceptor chain models.
• Investigation of higher-dimensional lattice models.

Main Results:

• The FBTS approach provides a reasonable balance between accuracy and computational cost for simulating these dynamics.
• Short-time exciton dissociation dynamics were investigated in various dimensional models.
• Dimensionality was assessed for its effect on initial charge carrier generation steps.

Conclusions:

• The FBTS method is a viable computational tool for studying OPV dynamics.
• Understanding interfacial dynamics is crucial for optimizing organic photovoltaic performance.
• Further research into dimensionality effects can guide the design of more efficient OPVs.