# Improved Energy Pooling Efficiency Through Inhibited Spontaneous Emission

## TL;DR

This study demonstrates that placing molecules in a tuned conductive cavity enhances energy pooling efficiency by inhibiting spontaneous emission and leveraging the Purcell effect, doubling efficiency in a model system.

## Contribution

It introduces a kinetic model combining quantum electrodynamics and ab initio data to quantify cavity effects on energy pooling efficiency.

## Key findings

- Energy pooling efficiency increased from 23% to 47% in a cavity.
- Inhibited spontaneous emission extends donor lifetime.
- Purcell effect enhances acceptor emission rate.

## Abstract

The radiative lifetime of molecules or atoms can be increased by placing them within a tuned conductive cavity that inhibits spontaneous emission. This was examined as a possible means of enhancing three-body, singlet-based upconversion, known as energy pooling. Achieving efficient upconversion of light has potential applications in the fields of photovoltaics, biofuels, and medicine. The affect of the photonically constrained environment on pooling efficiency was quantified using a kinetic model populated with data from molecular quantum electrodynamics, perturbation theory, and ab initio calculations. This model was applied to a system with fluorescein donors and a hexabenzocoronene acceptor. Placing the molecules within a conducting cavity was found to increase the efficiency of energy pooling by increasing both the donor lifetime and the acceptor emission rate--i.e. a combination of inhibited spontaneous emission and the Purcell effect. A model system with a free-space pooling efficiency of 23% was found to have an efficiency of 47% in a rectangular cavity.