Diffusion mechanism of exciplex. 2. Energy transfer mechanism

TL;DR

This paper investigates the diffusion mechanism of exciplexes in organic optoelectronic devices, revealing that energy transfer occurs mainly through a Dexter-type exchange process, which impacts device performance.

Contribution

It demonstrates that exciplex diffusion is primarily driven by Dexter-type energy transfer, providing new insights into exciplex behavior in organic electronics.

Findings

Energy transfer occurs via Dexter mechanism

ET rate decreases exponentially with distance

Diffusion influences device performance

Abstract

Excited-state charge-transfer complexes (exciplexes) have been actively exploited in organic optoelectronic devices to improve performance; however, diffusion of exciplexes has not been actively studied despite its influence on performance due to the lack of apparent charge-transfer absorption. In the preceding paper, we studied the energy transfer (ET) from exciplexes to exciplex-forming pairs in relation to the charge-transfer absorption of the exciplex state, resulting in the exciplex diffusion. In this paper, we report that the ET takes place dominantly via the Dexter-type exchange mechanism, from the exponential decrease of the ET rate constant with separation between exciplexes.