A low-cost polymerized hole-transporting material for high performance planar perovskite solar cells

A low-cost, small molecular monomer, 5'-bis(9-(4-vinylbenzyl)-2-carbazol)-2,2'-bithiophene, termed VB-CB, is designed, synthesized, and polymerized to form a uniform film as the hole-transporting material for the fabrication of inverted planar perovskite solar cells with high performance. The presence of a suitable energy level in the polymerized VB-CB layer can effectively promote the transport of holes and block electrons from the perovskite layer, thus decreasing photon energy loss due to charge recombination. Designing perovskite solar cells with polymerized VB-CB as the hole-transporting material helps us to obtain a high power conversion efficiency of 17.58% with small hysteresis effect, which is higher than that with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole-transporting material. Additionally, as compared to PEDOT:PSS, the devices with polymerized VB-CB exhibit better stability under one sun illumination at maximum power point tracking, such that the T80 of the champion devices could exceed 1000 h. The results suggest that the polymerized VB-CB is a suitable hole-transporting material for commercial applications in planar perovskite solar cells, given its low-cost, high efficiency, and good stability. Published under an exclusive license by AIP Publishing.

Automated summary

A low-cost polymerized VB-CB is designed as a hole-transporting material for inverted planar perovskite solar cells, resulting in a high power conversion efficiency of 17.58% with minimal hysteresis. Compared to PEDOT:PSS, devices with VB-CB exhibit better stability under one sun illumination, with a T80 exceeding 1000 hours. The results suggest that polymerized VB-CB is a suitable material for commercial applications in planar perovskite solar cells due to its low-cost, high efficiency, and good stability.