Photo-annealing treatment has successfully been demonstrated in organic solar cells (OSCs) with solution-processable titanium (diisopropoxide) bis(2,4-pentanedionate) (TIPD) as an electron extraction layer; this process was shown without thermal annealing treatment. The power conversion efficiency (PCE) is quite low in the initial stage, though it dramatically increases following constant light illumination and reaches a saturated state after 9 min of light illumination. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and ultraviolet photoemission spectroscopy (UPS) were used, and they showed that the TIPD molecules decomposed and formed stable TiO bonds. According to photocurrent density-effective voltage curve (Jph-Veff), short-circuit current density (JSC) and open-circuit voltage (VOC) value under different light intensity, the photo-annealed TIPD-based OSCs showed efficient charge transport and suppressed charge recombination. Thus, after a fresh TIPD solution was spin-coated onto the indium tin oxide (ITO) surface and photo-annealed for 9 min, the OSCs showed the highest photovoltaic performance compared to ZnO-based OSCs.