Tailoring the Photovoltaic Performance of Inverted Hybrid Solar Cells by Replacing PEDOT:PSS with V2Ox as Hole- Extraction Layer.

For nanoscale fabrication of organic photovoltaic device, the utilization of a hole extraction layer (HEL) is essential to prevent the wrong flow of charge carriers and overcome the Schottky barrier at electrode-polymer interface. In recent years, the degradation issue of PEDOT:PSS based device which arises from its acidic nature and extremely hygroscopic properties has prompted researchers to find an appropriate transition metal oxide as replacement. In current work, we introduced an entirely solution-processed substoichiometric vanadium oxide (V2Ox) as HEL in inverted polymer:fullerene based device. We demonstrated the efficiency of substoichiometric V2Ox layer in enhancing the device performance of inverted organic solar cells, with the PCE of the device increased from 1.91 to 2.89%. The V2Ox prepared herein was found to exhibit broad optical absorption, highly selective charge transporting properties and excellent film transparency. A robust correlation between the hole extraction nature and electronic band structure of V2Ox was also established in this work. [ABSTRACT FROM AUTHOR]