Synthesis and Field Emission of ZnO Nanostructures on CuO Catalyzed Porous Silicon Substrate

Mass production of ZnO nanobelts and hexagonal nanorods has been successfully synthesized on CuO catalyzed porous silicon (PS) using a simple vapour--solid (VS) growth method. A comparison of their morphologies is investigated by scanning electron microscopy (SEM). The transmission electron microscopy (TEM) confirms that ZnO nanobelts and nanorods are single crystalline with the growth direction of (0110) and (0001), respectively. Field emission tests indicate that the ZnO nanostructures on porous silicon have low turn-on field of about 3.6V/μm (at 1.0μA/cm²) and the threshold field of about 8.3V/μm (at 1.0mA/cm²), high emission site density (ESD) of approximately 10⁴cm^-2.