Novel unsymmetrical push-pull squaraine chromophores for solution processed small molecule bulk heterojunction solar cells

► Push-pull squaraine chromophores, [TPA-bisHT-HP]-X-Ind [X: SQ, diCNSQ] were characterized. ► The diCNSQ presented significantly the red-shifted absorption compared to SQ. ► The diCNSQ plays an important role as effective e-accepting and charge separating mediator.