Anisotropic excitation transfer to acceptors randomly distributed on surfaces

Area of Science:

• Physical Chemistry
• Spectroscopy
• Materials Science

Background:

• Energy transfer between molecules is crucial in various chemical and physical processes.
• Anisotropic dipolar interactions and orientational disorder significantly influence energy transfer dynamics.
• Understanding these effects is key for applications in areas like organic electronics and photochemistry.

Purpose of the Study:

• To derive exact expressions for the ensemble-averaged excitation decay of a donor molecule.
• To investigate energy transfer to randomly distributed acceptors on a surface via anisotropic dipolar interactions.
• To analyze the impact of positional and orientational disorder on energy transfer efficiency.

Main Methods:

• Development of exact analytical expressions for energy transfer decay.
• Consideration of various scenarios including random acceptor positions and orientations, and different donor orientations.
• Numerical calculations of decay laws for comparison and validation of analytical models.
• Determination of the domains of validity for Förster-like expressions.

Main Results:

• Exact expressions for ensemble-averaged decay were derived, accounting for anisotropic dipolar interactions.
• The influence of positional and orientational disorder on energy transfer was quantified.
• Analytical Förster-like expressions were evaluated for different disorder configurations.
• Domains of validity for these approximations were established through comparison with numerical results.

Conclusions:

• The study provides a comprehensive theoretical framework for understanding energy transfer in disordered systems.
• The derived expressions and validity domains are essential for accurate modeling of photophysical processes.
• This work contributes to the fundamental understanding of excitation energy transfer in complex molecular arrangements.