Enhanced Interfacial Properties of Electrochemically Deposited ZnO Nano Structured Electrode

The electronic properties at the transparent conducting oxide (TCO)/semiconductor interface are crucial in optimizing the efficiency of light harvesting and storage devices. The back scattered current and surface defects of ZnO nanorods at interface limit the commercial level fabrication of device structures with this material system. Herein, a cost effective and scalable electro-nanofabrication technique has been utilized for the growth of ZnO nanorods over seeded TCO substrates. The electrochemical conditions for controlling ZnO nano rod morphology over the ZnO self-seeded transparent conducting oxide coated glass substrate are comprehensively investigated. The results show that the seed layer thickness, annealing environment for seeding and growth as well as processing temperatures are critical in optimizing the electronic properties at the interface. By controlling these parameters the back scattering current has been reduced to record minimum of 10(-7) A and the interfacial resistance has been minimized to 30 Omega. Photoluminescence spectroscopy and the Electrochemical Impedance spectroscopy are effectively used in this study for defect center analysis and interfacial characterization.