New efficient dyes containing tert-butyl in donor for dye-sensitized solar cells

A series of D–π–A organic sensitizers that contains two 4-tert-butylbenzene moieties in the donor part of triphenylamine group are designed and characterized. All these dyes comprise the same donor and acceptor units while the different aromatic units are introduced as linkers between the donor and acceptor units. It is found that the tuning of the HOMO and LUMO energy level can be conveniently achieved by alternating the conjugate bridge. The DSSCs based on LI-17 show the best light to electricity conversion efficiency of 5.35% (Jsc = 12.65 mA cm−2, Voc = 675 mV, ff = 0.63) under standard global AM 1.5 solar light conditions (100 mW cm−2), indicating that the introduction of tert-butyl groups may be able to play an anti-aggregation effect.

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► Four organic dyes with different bridge were applied in dye-sensitized solar cells.
► The tert-butyl group were first introduced into D–π–A organic sensitizers to play the role of anti-aggregation.
► The device based on sensitizer LI-17 achieved the efficiency of 5.35% without CDCA.