Fabricating high performance polymer photovoltaic modules by creating large-scale uniform films

Abstract A spray-coating method, named as partially overlapped spray-coating (POSC) with winding path, was developed to deposit homogenous film over large area and employed to fabricate polymer solar cell (PSC) modules. The photoactive layer consisting of the conjugated polymer PBTI3T and the fullerene derivative PCBM[70] was obtained by optimizing the ink formulations and spray-coating parameters, which determines the morphology and film thickness. The lab-scale PSC (0.09 cm2) fabricated by the POSC technique achieved a power conversion efficiency (PCE) of 6.63%, which is comparable to the spin-coated one. The POSC technique was then applied to up-scaling fabrication of PSC modules. A PCE as high as 5.27% was achieved for the module with 38.5 cm2 photoactive area, which is so far the highest one with comparable size, to the best of our knowledge. It shows the POSC technique developed in this work is very successful for fabricating high-performance PSC modules, which paves a new way for film deposition in continuous roll-to-roll production.