Room-temperature preparation of crystalline TiO2 thin films and their applications in polymer/TiO2 hybrid optoelectronic devices

Highly homogeneous crystalline TiO2 thin films with very low surface roughness were prepared by spin-coating of a TiO2 nanoparticle aqueous dispersion at room temperature without further heat treatment. Using these films as electron transporting layers, inverted structure hybrid photovoltaic cells (TiO2/P3HT) and light-emitting diodes (TiO2/F8BT) were demonstrated. The photovoltaic cells exhibited an energy conversion efficiency of 0.26%, which is similar to that of cells utilizing TiO2 layers sintered at high temperatures. Moreover, the light-emitting diodes showed an efficiency of 0.65 cd/A, which is higher than obtained from a reference inverted diode (0.1 cd/A). These measurements demonstrate that a properly designed nanoparticle casting route can help avoid high temperature crystallization or sintering steps for TiO2 thin films, paving the road for their use in conjunction with plastic substrates.

Homogeneous and smooth TiO2 thin films suitable for organic electronic applications can be prepared at room temperature by spin-coating of crystallized TiO2 nanoparticle dispersion without further heat treatment.Figure optionsDownload as PowerPoint slideHighlights
► Preparing TiO2 thin films at room temperature.
► Preparing TiO2 thin films by spin-coating of crystallized nanoparticle dispersion.
► TiO2 thin films suitable for organic electronics fabrication.