Orientation-engineered halide perovskite single-crystal cathodes for efficient field emission in nano vacuum channel transistors

Nano vacuum channel transistors (NVCTs) are increasingly recognized as a promising class of devices for high-frequency, radiation-hardened, and beyond-complementary metal-oxide-semiconductor (CMOS) electronics, yet their progress has been constrained by the low emission current, high turn-on voltage, and limited manufacturability. Here, we reported the first integration of halide perovskite single crystals (MAPbBr₃, MA stands for methylammonium) as the electron emitter in NVCTs, achieving performance levels incomparable to those using other cathode materials. Remarkably, even with a large vacuum channel length of ~ 230 nm, the devices delivered drain currents up to 1.26 mA and operated at a remarkably low turn-on voltage of 8 V in air, highlighting their exceptional emission capability. The perovskite-assisted NVCTs exhibited a robust gate modulation with negligible leakage and pronounced photo-responsivity, enabling potential electrical–optical joint control. Importantly, the devices were fabricated on display glass substrates using thin-film transistor-liquid crystal display (TFT-LCD) manufacturing processes, offering a pathway toward low-cost, scalable, and integrable nano-vacuum electronics. This work established perovskite single crystals as a new material platform for manufacturable, multifunctional vacuum electronics with relevance to the next-generation information and communication technologies.