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arXiv · 1511.06302

Photocell Optimisation Using Dark State Protection

Amir Fruchtman·Rafael Gómez-Bombarelli·Brendon W. Lovett·Erik M. Gauger
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Abstract

Conventional photocells suffer a fundamental efficiency threshold imposed by the principle of detailed balance, reflecting the fact that good absorbers must necessarily also be fast emitters. This limitation can be overcome by `parking' the energy of an absorbed photon in a dark state which neither absorbs nor emits light. Here we argue that suitable dark states occur naturally as a consequence of the dipole-dipole interaction between two proximal optical dipoles for a wide range of realistic molecular dimers. We develop an intuitive model of a photocell comprising two light-absorbing molecules coupled to an idealised reaction centre, showing asymmetric dimers are capable of providing a significant enhancement of light-to-current conversion under ambient conditions. We conclude by describing a roadmap for identifying suitable molecular dimers for demonstrating this effect by screening a very large set of possible candidate molecules.

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Amir Fruchtman, Rafael Gómez-Bombarelli, Brendon W. Lovett, Erik M. Gauger. 2016-08-05. Photocell Optimisation Using Dark State Protection. https://doi.org/10.1103/physrevlett.117.203603

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