不同基底的GaN纳米薄膜制备及其场发射增强研究

Preparation of nanostructured GaN films and their field emission enhancement for different substrates

采用脉冲激光沉积(PLD)方法在Si及SiC基底上制备了相同厚度的GaN纳米薄膜并对其进行了微结构表征及场发射性能测试分析.结果表明:基底对于GaN薄膜微结构及场发射性能具有显著的影响.在SiC基底上所制备的GaN纳米薄膜相对于Si基底上的GaN纳米薄膜,其场发射性能得到显著提升,其场发射电流可以数量级增大.场发射显著增强应源于纳米晶微结构及取向极化诱导增强效应.本研究结果表明,要获得优异性能场发射薄膜,合适基底及薄膜晶体微结构需要重点考虑.

Using pulsed laser deposition （PLD） method, we have prepared nanostructured GaN films of the same thickness on Si and SiC substrates, and analyzed their microstructure characterization and field emission properties. The results showed that the substrates of GaN nanostructured films had significant effect on the microstructure and field emission properties. Compared with the GaN nano-film on Si substrate, the field emission from the GaN nano-film on SiC substrate has been significantly improved： its field emission current was increased by orders of magnitude. The field emission enhancement should be originated from the nanocrystalline microstructure and its orientation polarization induced field enhancement effect. Results indicate that to prepare field emission films of Outstanding performance, appropriate substrates and crystal microstructures of the films are the key issues.