Fabrication of nanostructured ZnO thin films using self-assembled organic molecule templates and optical transitions

• ZnO nanostructured thin films are grown using electrodeposition technique.
• Organic surfactant molecules endorse self-assembled templates for ZnO growth.
• Self assembled different surface morphologies are obtained.
• Different morphologies alter the photoluminescence properties of ZnO.
• A defect energy level diagram is presented.

We report on the electrosynthesis of nanostructured zinc oxide (ZnO) thin films using organic molecule templates self-assembled on indium-doped tin oxide substrates in an aqueous medium. The organic molecule templates alter the morphology and microscopic defect configuration of the ZnO film having a hexagonal wurtzite structure. Low-temperature photoluminescence (PL) study reveals that the ZnO films exhibit ultraviolet (3.36 eV and 3.22 eV), violet (3.06 eV), blue (2.88 eV), and green (2.50 eV) emissions that originate from transitions related to deep-level (zinc interstitials and vacancies) and acceptor-like (ionized zinc vacancies) defect states. A defect energy level diagram based on the PL measurement is proposed.