陶瓷Al4C3薄膜厚度依赖的场发射特性研究

Study on Thickness-dependent Field Emission Characteristics of Ceramic Al4C3 Thin Films

采用简单的热化学输运方法,通过控制生长温度和时间,在钨箔上制备了不同厚度的Al_4C_3薄膜.通过扫描电镜(SEM)、X射线衍射(XRD)和拉曼光谱分析等手段对样品的形貌和结构进行了系列表征.场电子发射测试表明,厚度为300 nm、600 nm和1 000 nm的Al_4C_3薄膜的开启电压分别为4.2 V/μm、5.8 V/μm和8.6 V/μm(发射电流10 A/cm^2).这种现象可归因于绝缘Al_4C_3层的厚度和空间电荷效应引起的电子输运能力差异.

Al4C3 thin films with various thicknesses on tungsten foils were prepared using simple thermal chemical transport and consideration by controlling growing temperatures and time duration.SEM(scanning electron micrograph),XRD(x-ray diffraction)and Raman spectra analysis were employed to characterize the samples.Field emission measurement reveal that the Al4C3 thin film with thickness of 300 nm,600 nm and 1 000 nm own turn-on field(where emission current reaches 10μA/cm^2)of 4.2 V/μm,5.8 V/μm and 8.6 V/μm respectively.This phenomenon can be attributed to the electron transport capability discrepancy which is caused by the thickness of the insulated Al4C3 layers and space charge effect.