Work-function tuneable and aqueous solution-processed Cs sub(2)CO sub(3) for high-performance polymer solar cells

The authors demonstrate an aqueous solution-processed Cs sub(2)CO sub(3) thin film with an adjustable work function viaMoO sub(3) and/or Na sub(2)WO sub(4) doping. The doped Cs sub(2)CO sub(3) as a cathode interfacial layer is successfully used in poly(3-hexyl-thiophene) (P3HT)/indene-C sub(60) bisadduct (IC sub(60)BA) heterojunction based solar cells with improved open-circuit voltage and unaffected short-circuit current density. X-ray photoelectron spectroscopy (XPS) evaluation was conducted to verify the formation of the new composites of W-O-Cs and Mo-O-Cs after doping of MoO sub(3) and/or Na sub(2)WO sub(4) into Cs sub(2)CO sub(3). The change of the work function of MoO sub(3)- and/or Na sub(2)WO sub(4)-doped Cs sub(2)CO sub(3) was further confirmed by ultraviolet photoelectron spectroscopy (UPS) measurements.