Solution processed vertically stacked ZnO sheet-like nanorod p-n homojunctions and their application as UV photodetectors

One long-standing goal in the development of one-dimensional nanostructured electronic devices is to facilitate the ongoing trend of miniaturization so as to enable ultralow power operation. Zinc oxide (ZnO) nanostructures, which have a direct and wide bandgap, are a central component in numerous electronic and optoelectronic applications. Here, we address vertically stacked ZnO sheet-like nanorod (SLNR) p-n homojunctions composed of single-crystalline undoped (n-type) and Li-doped (p-type) ZnO SLNRs by a multi-step solution-based hydrothermal route. Precise control of the molar concentration represented one of the basic factors in ensuring that the p-n homojunctions possessed appropriate densities and suitable morphologies. An extensive analysis of the luminescence features was carried out in order to identify p-type conduction in the Li-doped ZnO SLNRs. In addition, the SLNR-based p-n homojunctions exhibited distinct electrical features that validated their potential use as ultraviolet photodetectors, thereby spurring progress in the development of practical optoelectronics.