Abstract
In this thesis, majority of the process flow of TiOx layer is current driven. Most of the reported data about solar cell based on sol-gel processed titanium oxide in the literature use high temperature sintering process (400–500℃), and must be place in air for a few hours. Using the thermal-deposition-processed titanium oxide as a transparent buffer layer (T=97±1.5% under TiOx thickness=10nm) at low-temperature fabrication method during deposition without the need for a high temperature sintering process, the polymer solar cells have the potential on device pattern design, simple process, and flexible substrates application compared to the sol-gel process titanium oxide. We demonstrate inverted polymer solar cell based on the P3HT:PCBM blend structure with additions of TiOx buffer layer as the electron collecting layer (ECL) and V2O5 layer as the hole collecting layer(HCL) exhibit more excellent characteristics with a power conversion efficiency of 3.154% than 0.591% without TiOx layer under AM1.5G 100 mW/cm2 irradiation. The improved device performance is attributed to an improved polymer/ITO contact, more efficient electron extraction, and better hole blocking properties. On the other hand, application of this structure for multiple-stacking polymer solar cells will be also discussed. It indeed increases the possibility of applying structure for multiple-stacking polymer solar cells to achieve the wider absorption spectrum.