Microcavity effects on the generation, fluorescence, and diffusion of excitons in organic solar cells

TL;DR

This paper investigates how microcavity effects influence exciton behavior in organic solar cells, showing that optimizing device geometry and dielectric properties can reduce fluorescence losses, extend exciton diffusion length, and enhance overall efficiency.

Contribution

It introduces a detailed analysis of microcavity effects on exciton diffusion and fluorescence in organic solar cells, proposing strategies to improve device performance.

Findings

Fluorescence losses vary with exciton position and quantum efficiency.

Proper geometrical and dielectric design can suppress fluorescence.

Enhanced diffusion length leads to improved solar cell efficiency.

Abstract

We compute the short-circuit diffusion current of excitons in an organic solar cell, with special emphasis on fluorescence losses. The exciton diffusion length is not uniform but varies with its position within the device, even with moderate fluorescence quantum efficiency. With large quantum efficiencies, the rate of fluorescence can be strongly reduced with proper choices of the geometrical and dielectric parameters. In this way, the diffusion length can be increased and the device performance significantly improved.