A ZnO asperity-covered carbon nanotube (CNT) device has been provided, along with a corresponding fabrication method. The method comprises: forming a substrate; growing CNTs from the substrate; conformally coating the CNTs with ZnO; annealing the ZnO-coated CNTs; and, forming ZnO asperities on the surface of the CNTs in response to the annealing. In one aspect, the ZnO asperities have a density in the range of about 100 to 1000 ZnO asperities per CNT. The density is dependent upon the deposited ZnO film thickness and annealing parameters. The CNTs are conformally coating with ZnO using a sputtering, chemical vapor deposition (CVD), spin-on, or atomic layer deposition (ALD). For example, an ALD process can be to deposit a layer of ZnO over the CNTs having a thickness in the range of 1.2 to 200 nanometers (nm).