Daiber Benjamin, van den Hoven Koen, Futscher Moritz H, Ehrler Bruno
AMOLF, Center for Nanophotonics, Science Park 102,1098 XG Amsterdam, The Netherlands.
ACS Energy Lett. 2021 Aug 13;6(8):2800-2808. doi: 10.1021/acsenergylett.1c00972. Epub 2021 Jul 20.
Singlet fission is a carrier multiplication mechanism that could make silicon solar cells much more efficient. The singlet-fission process splits one high-energy spin-singlet exciton into two lower-energy spin-triplet excitons. We calculated the efficiency potential of three technologically relevant singlet-fission silicon solar cell implementations. We assume realistic but optimistic parameters for the singlet-fission material and investigate the effect of singlet energy and entropic gain. If the transfer of triplet excitons occurs via charge transfer, the maximum efficiency is 34.6% at a surprisingly small singlet energy of 1.85 eV. For the Dexter-type triplet energy transfer, the maximum efficiency is 32.9% at a singlet energy of 2.15 eV. For Förster resonance energy transfer (FRET), the triplet excitons are first transferred into a quantum dot, from which they then undergo FRET into silicon. For this transfer mechanism, the maximum efficiency is 28.% at a singlet energy of 2.33 eV. We show that the efficiency gain from singlet fission is larger the more efficient the silicon base cell is, which stands in contrast to tandem perovskite-silicon solar cells.
单线态裂变是一种载流子倍增机制，它可以使硅太阳能电池的效率大幅提高。单线态裂变过程将一个高能自旋单重态激子分裂为两个低能自旋三重态激子。我们计算了三种与技术相关的单线态裂变硅太阳能电池实施方案的效率潜力。我们为单线态裂变材料假设了现实但乐观的参数，并研究了单线态能量和熵增的影响。如果三重态激子通过电荷转移发生转移，在令人惊讶的低单线态能量1.85 eV时，最大效率为34.6%。对于德克斯特型三重态能量转移，在单线态能量为2.15 eV时，最大效率为32.9%。对于福斯特共振能量转移（FRET），三重态激子首先转移到量子点中，然后从量子点经历FRET进入硅中。对于这种转移机制，在单线态能量为2.33 eV时，最大效率为28.%。我们表明，硅基电池效率越高，单线态裂变带来的效率提升就越大，这与串联钙钛矿-硅太阳能电池形成对比。
