Singlet fission and tandem solar cells reduce thermal degradation and enhance lifespan

The economic value of a photovoltaic installation is proportional to both its lifetime and power conversion efficiency. Progress towards the latter includes mechanisms to circumvent the Shockley- Queisser limit, such as tandem designs and multiple exciton generation (MEG). Here we demonstrate that there are also significant lifespan advantages from MEG enhanced silicon cells: (i) Multiple exciton generation reduces the cell operating temperature, increasing the device lifetime; (ii) the device architecture can completely circumvent the need for current-matching; and (iii) upon degradation, tetracene, a candidate singlet fission (a form of MEG) material, is transparent to the solar spectrum. The combination of (ii) and (iii) mean that the primary silicon device will continue to operate with high efficiency even if the singlet fission layer degrades. The lifespan advantages of MEG enhanced silicon cells, from a module perspective, are compared alongside the promising perovskite/silicon tandem and conventional c-Si modules.