Fabricating the solution-processable inverted photovoltaic devices by the dip-coating method

All solution processable photovoltaic (PV) devices have been great interests in the past decade and different processing methods have been explored to produce the PV devices. In this paper, the dip-coating method was studied to fabricate core layers in the inverted polymer photovoltaic devices, which demonstrates that the dip-coating technology has its potential to produce large area PV devices. The crystallinity of the active layers by the dip-coating method can be improved under the condition of the extended drying rate. Light absorption spectra and X-ray diffraction (XRD) patterns of the active layers were investigated to confirm the improved crystallinity of the active layers. Various morphologies of the dip-coated layers were observed by the atomic force microscopy (AFM). The best PV device achieved ~3.4% power conversion efficiency.