Surface-roughness-assisted formation of large-scale vertically aligned CdS nanorod arrays via solvothermal method

► CdS nanorod arrays were synthesized on several different substrates. ► The morphology of the substrate was quite critical for the CdS seed layers. ► The morphology of all the substrates were studied by atomic force microscopy. ► Each sample had a non-linear I-V characteristic for a −2 V to 2 V sweep. ► The optical properties of the samples were tested.