Superior Stability and Efficiency Over 20% Perovskite Solar Cells Achieved by a Novel Molecularly Engineered Rutin-AgNPs/Thiophene Copolymer.

Perovskite solar cells (PSCs) with efficiencies greater than 20% have been realized mostly with expensive spiro-MeOTAD hole-transporting material. PSCs are demonstrated that achieve stabilized efficiencies exceeding 20% with straightforward low-cost molecularly engineered copolymer poly(1-(4-hexylphenyl)-2,5-di(thiophen-2-yl)-1H-pyrrole) (PHPT-py) based on Rutin-silver nanoparticles (AgNPs) as the hole extraction layer. The Rutin-AgNPs additive enables the creation of compact, highly conformal PHPT-py layers that facilitate rapid carrier extraction and collection. The spiro-MeOTAD-based PSCs show comparable efficiency, although their operational stability is poor. This instability originated from potential-induced degradation of the spiro-MeOTAD/Au contact. The addition of conductive Rutin-AgNPs into PHPT-py layer allows PSCs to retain >97% of their initial efficiency up to 60 d without encapsulation under relative humidity. The PHPT-py/ Rutin-AgNPs-based devices surpass the stability of spiro-MeOTAD-based PSCs and potentially reduce the fabrication cost of PSCs.