Morphology and optoelectronic properties of ZnO rod array/conjugated polymer hybrid films

Vertically aligned zinc oxide (ZnO) nanorods were grown on the ITO glass and then coated with the conjugated polymer poly(2,3-dibutoxy-1,4-phenylene vinylene) (DB-PPV) to make the hybrid films. Nanorods with different diameters were synthesized to study the influences of ZnO nanorod morphology and polymer infiltration on the photocurrent and optical properties of the hybrid films. Increasing the growth time leads to the formation of ZnO rod array with large rod diameter, large surface area and small inter-rod distance. Small inter-rod distance hinders the filling of DB-PPV into the porous ZnO rod microstructure and lowers the PN junction area. It leads to lower photocurrent of the hybrid film. The red shift of the photoluminescence spectra suggests that filling the polymer into the ZnO rod microstructure favors more planar molecular orientations of the conjugated polymers and leads to an increase in the effective conjugation length.