Ultrafast charge separation driven by differential particle and hole mobilities

Area of Science:

• Computational Chemistry
• Quantum Dynamics
• Materials Science

Background:

• Understanding intramolecular charge separation is crucial for designing advanced electronic materials.
• Simulating the time evolution of electronic wavefunctions provides detailed insights into molecular dynamics.

Purpose of the Study:

• To simulate and compare the evolution of local excitations into intramolecular charge-separated states across various molecular systems.
• To investigate the influence of chemical composition on charge separation dynamics.

Main Methods:

• Direct simulation of electronic wavefunction time propagation.
• Utilizing the extended second-order algebraic diagrammatic construction (ADC(2)-x) method to account for electron correlation.
• Analyzing charge mobility and spreading based on molecular doping with particles or holes.

Main Results:

• Charge separation dynamics are tunable via chemical composition, affecting particle or hole mobility.
• Initially, charges oscillate between molecular ends, then spread across the entire molecule at longer times.
• Charge separation is observed in asymmetric systems, paving the way for selective excitation and dynamic studies.

Conclusions:

• The study demonstrates a direct simulation approach to track charge separation processes.
• Chemical doping significantly impacts charge carrier mobility and distribution within conjugated systems.
• The findings support the potential for experimental control over charge separation dynamics in tailored molecular systems.