Synthesis of zinc oxide colloidal nanorods for inorganic–organic hybrid photodiode application

In this paper, ZnO colloidal nanorods were synthesized by a simple wet chemical method at low temperature. The morphologies, crystalline structure and ultraviolet–visible (UV–Vis) absorption spectrum of the synthesized ZnO nanorods were investigated by field-emission scanning-electron microscopy, transmission electron microscopy, X-ray diffraction and UV–Vis spectroscopy, respectively. The results of these measurements showed that the samples exhibited rodlike with a wurtzite structure, 15 nm in diameter and 100 nm in length. Furthermore, a simple inorganic–organic hybrid heterojunction photodiode consisted of the ZnO nanorods and copper (II) phthalocyanine was fabricated. The device showed good rectifying behaviors in the dark and under illumination, its maximum rectifying ratio, turn on voltage, ideality factor and reverse saturation current in the dark were 641.9 at ±1.95 V, 1.1 V, 4.7 and 3.39 × 10−8 A, respectively. In addition, under 40 mW/cm2 illumination power, the rectifying ratio of the photodiode was 32.5 at ±1.95 V.