Improved Energy Pooling Efficiency through Inhibited Spontaneous Emission

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.

Resonance Energy Transfer: From Fundamental Theory to Recent Applications

“…The matrix element for energy pooling has an analogous form to Equation (35); the only difference is that the superscript m0 on A (which is now a donor) becomes 0n and the superscript 00 on M (now the acceptor) becomes s0, where s signifies a doubly excited molecule. In recent years, Lusk et al have demonstrated energy pooling experimentally [146] and discovered, among other advances, that the efficiency of energy pooling can be improved within a cavity [147][148][149]. Lately, moreover, they have studied the time-inverse mechanism of energy pooling, known as quantum cutting, which involves the excitation on A transferring to both D molecules [150].…”

Polariton mediated resonance energy transfer in a fluid

“…[40][41][42][43] Some of these include energy pooling schemes such as twin-donor energy migration, cooperative and accretive mechanisms that facilitate upconversion, downconversion, and sensitization in rare-earth doped systems, as well as cavity enhanced three-body upconversion. [44][45][46][47][48] A few publications have even dealt with RET involving four bodies. [49][50][51][52] In this work, we seek to understand the relative contribution of pure-amplitude and phase interference cross terms to the overall rate of RET in an isotropic and disordered fluid.…”

Near-Zone Mediation of RET by One and Two Proximal Particles

“…Studies of pair RET and the role of an additional particle in mediating transfers have not only been limited to atomic and molecular systems but also have included quantum dots, nanowires, and dimensionally constrained nanostructures. − The influence of two- and three-body RET in enabling upconversion, sensitization, and downconversion in rare earth doped ionic materials via distinct cooperative and accretive mechanisms has been studied too . Theory has also been extended to cover transfer of energy among four centers, specifically the energy pooling scenario where three of the four sites are pre-excited and transfer their energy to the fourth species and the variety of possible pathways by which this funneling process can occur, supplementing the three-center energy pooling case, and work examining the enhancement of three-body upconversion in a cavity. , Higher multipole contributions to the two-body transfer rate have also been calculated. − These contributions become important when the size of the chromophore is comparable to or larger than the donor–acceptor displacement. The long wavelength or electric dipole approximation no longer holds, and the effects of magnetic dipole and electric quadrupole coupling need to be treated.…”

“…21 Theory has also been extended to cover transfer of energy among four centers, 22 specifically the energy pooling scenario where three of the four sites are pre-excited and transfer their energy to the fourth species and the variety of possible pathways by which this funneling process can occur, supplementing the three-center energy pooling case, 23 and work examining the enhancement of three-body upconversion in a cavity. 24,25 Higher multipole contributions to the two-body transfer rate have also been calculated. 26−29 These contributions become important when the size of the chromophore is comparable to or larger than the donor−acceptor displacement.…”