Performance improvement of P3HT/TiO2 coaxial heterojunction polymer solar cells by introducing a CdS interface modifier

► CdS QDs sensitized P3HT/TiO2 solid coaxial heterojunction solar cells are fabricated. ► The Voc of such sensitized polymer solar cell reaches the value as high as 0.72 V. ► 4.5 times higher PCE obtains as compared with the non-sensitized cell. ► The dominate roles of CdS QDs sensitization on the PCE enhancement are investigated.