Exciton Fission Enhanced Silicon Solar Cell

TL;DR

This paper introduces a novel silicon solar cell design that uses molecular exciton fission and sequential charge transfer to surpass traditional efficiency limits, achieving over 138% charge generation efficiency per photon.

Contribution

It demonstrates a scalable method combining molecular exciton fission with silicon cells, overcoming previous coupling challenges and exceeding quantum efficiency limits.

Findings

Charge generation efficiency surpasses 138% per photon.

Sequential charge transfer effectively couples molecular states to silicon.

New scalable approach for high-efficiency photovoltaics.

Abstract

While silicon solar cells dominate global photovoltaic energy production, their continued improvement is hindered by the single junction limit. One potential solution is to use molecular singlet exciton fission to generate two electrons from each absorbed high-energy photon. We demonstrate that the long-standing challenge of coupling molecular excited states to silicon solar cells can be overcome using sequential charge transfer. Combining zinc phthalocyanine, aluminum oxide, and a shallow junction crystalline silicon microwire solar cell, the peak charge generation efficiency per photon absorbed in tetracene is (138 +- 6)%, comfortably surpassing the quantum efficiency limit for conventional silicon solar cells and establishing a new, scalable approach to low cost, high efficiency photovoltaics.