Ternary-organic photovoltaics with J71 as donor and two compatible nonfullerene acceptors

Recombining the advantages on photovoltaic parameters of two binary-organic photovoltaics (OPVs) into one ternary cell is an efficient strategy for selecting materials, in addition to the absorption spectra complementary among the used materials. The binary-OPVs with J71:BTP-4F-12 exhibit a power conversion efficiency (PCE) of 11.70%, along with a short-circuit-current-density (J(SC)) of 23.61 mA cm(-2), an open-circuit-voltage (V-OC) of 0.841 V and a fill factor (FF) of 58.99%. Although the relatively low PCE of 10.92% and J(SC) of 16.59 mA cm(-2) are achieved in J71:ITIC-based binary-OPVs, the V-OC of 0.935 V and FF of 70.40% are impressive compared with J71:BTP-4F-12-based OPVs. Optimal ternary-OPVs are achieved with J71:BTP-4F-12:ITIC as active layers by weight ratio of 1:0.48:0.72, delivering a markedly increased PCE of 13.05% with a V-OC of 0.903 V, a J(SC) of 21.27 mA cm(-2) and a FF of 68.20%. An over 11.5% PCE improvement is obtained by recombining the advantages of binary-OPVs into ternary-OPVs with ITIC as photon harvesting reinforcing agent and morphology regulator. The good compatibility between BTP-4F-12 and ITIC provides large room to well optimize their relative content for achieving the well balanced three key photovoltaic parameters of ternary-OPVs.

Automated summary

The recombination of advantages from two binary-organic photovoltaics (OPVs) into a ternary cell, with ITIC as a photon harvesting reinforcing agent and morphology regulator, leads to over 11.5% improvement in power conversion efficiency. The good compatibility between BTP-4F-12 and ITIC allows for optimizing their relative content to achieve a well balanced three key photovoltaic parameters in ternary-OPVs.