Influence of the substrate material on the surface morphology of electrochemically deposited ZnO layers

In this paper we report results of fabrication of ordered ZnO nanorods (NRs) or nanowalls (NWs) electrochemically deposited on different highly conductive substrates. The following types of conductive substrates have been used: (i) highly doped p-type multi-crystalline Si, and (ii) copper thin plates. The influence of a seeding Ag layer deposited on multi-Si substrates on the growth of ZnO NRs has been studied as well. It is observed that morphology of the deposited ZnO structures depends strongly on the type of the substrate used. It is found that ZnO structures with different shapes, such as NRs, nanotubes or NWs can be grown on top of highly conductive substrates used in this work. It is observed that optical reflection of the deposited layers depends on the substrate used as well as on the time of the electrochemical deposition of ZnO layers. It was found that: (i) for ZnO NWs/Cu structures, diffused reflection exhibit strong enhancement compared to pure Cu substrate; (ii) in case of ZnO NRs/Si structures reflection is decreased compared to that for pure Si substrate. Possible applications of ZnO NRs or NWs-based structures for the processing of advanced Si-based solar cells are discussed.