[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - High-frequency photocathode based on CNT-yarn emitter and GaAs photoswitch

摘要： A high frequency photocathode based on a carbon nanotube (CNT)-yarn in series to a semi-insulating (s.i.) GaAs was fabricated and used for field electron emission in a diode configuration. This hybrid two-chip technology allows the separate optimization of the yarn emitter and the photoswitch. This concept can overcome the capacitance limitations of miniaturized high-frequency vacuum tubes. The used CNT yarn emitter with 20 μm diameter had a threshold electric fields of ~1.8 V/μm (defined at 1mA/cm2) with a stable field emitter current up to 400 μA. The high-voltage photomodulation was up to 100 MHz.