Dendrimers with benzothiazole–benzoxazole surface groups and electron transporting triazole as bridging units and diphenyl sulfone as core unit were synthesized successfully by Cu(I)-catalysed Huisgen ‘click reaction’ using a convergent approach. All the dendrimers exhibit excellent optical and electrochemical properties. Higher-generation dendrimers exhibit better current generating capacity and show better power conversion efficiency than lower-generation dendrimers when used as additives in dye-sensitized solar cells.