Planar GaN Field Electron Emission Vacuum Transistors with Angled Gates

Field-emission vacuum transistors (FEVTs) have emerged as a promising candidate for next-generation high-frequency electronics due to their ballistic charge transport characteristics. Nevertheless, the reported FEVTs confront a performance trade-off: the enhancement of gate controllability of the emitter potential barrier inevitably induces a substantial increase in gate leakage current, forming a critical bottleneck for device applications. To address this challenge, we propose a planar GaN-based FEVT with dual-angled-gate architecture to co-optimize the gate controllability and gate leakage current of the device. The FEVTs with 45° gate angle perform at a low turn-on voltage (18.6 V) and provide a high transconductance (0.258 nS) alongside a high anode-to-cathode current ratio (68%). Notably, the device maintains stable current operation across a wide temperature range (300–575 K), highlighting its robustness against high temperature.