Field-emission triode of low-temperature synthesized ZnO nanowires

A field-emission triode based on the low-temperature (75°C) and hydrothermally synthesized single-crystalline zinc-oxide nanowires (ZnO NWs) grown on Si substrate with a silicon dioxide (SiO₂) insulator was fabricated for the controllable field-emission device application. Field-emission measurement reveals that the ZnO NWs fabricated on the Si substrate exhibit a good emission property with the turn-on electric field and threshold electric field (current density of 1 mA/cm²) of 1.6 and 2.1 V/μm, respectively, with a field enhancement factor β of 3340. The field-emission properties of the ZnO NW-based triode exhibit the controllable characteristics. The well-controlled field-emission characteristics can be divided into three parts: gate leakage region, linear region, and saturation region. Therefore, this study provides a low-temperature field-emission triode fabrication process that is compatible with the Si-based microelectronic integration, and the field-emission measurements also reveal that the emission behavior can be well controlled by adopting the triode structure.