Role of TiO2 Nanotube on Improvement of Performance of Hybrid Photovoltaic Devices

The performance of TiO2 nanotubes in bulk heterojunction of poly (2-methoxy-5-(2'-ethylhexyloxy)-1, 4-phenylenevinylene) (MEH-PPV)/TiO2 nanotubes is investigated. The transport properties are studied by using the time-of-flight technique (TOF). The carrier mobilities of both holes and electrons are not improved for the MEH-PPV:TiO2 composites compared with the pristine MEH-PPV. However, photoluminescence under the influence of the electric field indicates that the dissociation of excitons in the MEH-PPV:TiO2 composites, which is facilitated by photoinduced charge transfer, only requires a smaller electric field.