Electronic, optical and charge transfer properties of α,α′-bis(dithieno[3,2-b:2′,3′- d]thiophene) (BDT) and its heteroatom-substituted analogues

► The designed analogues where sulfur was substituted by NH (NHBDT) and by oxygen (OBDT) are blue shifted. ► The BH substituted one (BHBDT) is red shifted. ► The IP of NHBDT and OBDT are smaller than BDT revealed that injection barrier for hole would be small. ► The EA, IP and balanced hole and electron reorganization energies of BHBDT showed that it would be good ambipolar material.