本文采用激光脉冲沉积系统在SiC基底上制备了GaN/AlN/GaN多层纳米结构薄膜,探索了多层纳米薄膜量子结构增强场发射性能.X射线衍射和扫描电子显微镜结果表明,已成功制备出了界面清晰、结晶良好的GaN/AlN/GaN多层纳米薄膜.场发射测试结果表明:多层纳米薄膜结构相对于GaN和AlN单层纳米薄膜,其场发射性能得到显著提升.其开启电场低至0.93V/μm,电流密度在5.5V/μm时已经能够达到30mA/cm^2.随后进一步分析了纳米结构增强场发射机理,电子在GaN/AlN/GaN多层纳米薄膜结构中的量子阱中积累使其表面势垒高度显著下降,并通过共振隧穿效应进一步提高电子的透过概率,从而使场发射性能极大提高.研究结果将为应用于高性能场发射器件的纳米薄膜材料的制备提供一种好的技术方案.
We report on the electron field emission(FE) from multi-layer AlGaN nanofilm grown by pulsed laser deposition,and the investigation of the multi-layer quantum structure effect on the field emission performance. The results show that the as-grown film has a good crystallinity, and the thickness values of GaN, AlN, and GaN film are 25 nm, 50 nm,and 25 nm, respectively. The FE measurement indicates that compared with single layer, the multilayer filmhas a low turn-on field and large threshold current. The turn-on filed is found to be 0.93 V/μm, and the electric current density reaches to 30 m A/cm^2 at 5.5 V/μm. The improvement of the FE performance is attributed to resonant tunneling in the quantum well structure, and the accumulated electrons lower the effective surface barrier. The outstanding performance of multi-layer filed emission film should provide a feasible technical solution for large current and high power density thin film field emission device.