An asymmetric small-molecule donor enables over 18% efficiency in ternary organic solar cells

An asymmetric small-molecule donor TTBT-R, incorporated with benzo[2,1-b:3,4- b ′]dithiophene derivative as the core, was exploited for ternary OSCs, and the ternary OSCs base on PM6:Y6 as the host and TTBT-R as the guest achieved a PCE of 18.07%.