Solution-Processed MoO3 Thin Films As a Hole-Injection Layer for Organic Solar Cells

We report on a sol-gel-based technique to fabricate MoO3 thin films as a hole-injection layer for solution-processed or thermally evaporated organic solar cells. The solution-processed MoO3 (sMoO(3)) films are demonstrated to have equal performance to hole-injection layers composed of either PEDOT:PSS or thermally evaporated MoO3 (eMoO(3)), and the annealing temperature at which the sol-gel layer begins to work is consistent with the thermodynamic analysis of the process. Finally, the shelf lifetime of devices made with the sMoO(3) is similar to equivalent devices prepared with a eMoO(3) hole-injection layer.