薄膜型平栅极FED背光源的制备及性能研究

Fabrication and Properties of Film-planar-gate Field Emission Back Light Unit

利用磁控溅射和光刻技术在玻璃基底上制备薄膜型平栅极场发射阴极阵列,采用电泳工艺将碳纳米管(CNTs)发射材料转移到薄膜型平栅结构的阴极电极表面,借助光学显微镜和扫描电镜观测薄膜型平栅极场发射阴极阵列。利用Ansys软件模拟阴栅间距对阴极表面电场分布的影响,优化其结构参数,对其场发射特性进行了讨论。实验结果表明,CNTs能均匀地分散在平栅型结构的阴极表面,当电场强度为2.4 V/μm时,器件发射电流密度达到1.8 mA/cm2,亮度达3 000cd/m2,均匀性为90%,能稳定发射28 h,且具有较好的栅控作用。该薄膜型平栅极背光源技术简单、成本低,为将来制备新一代大面积场发射背光源提供了可行性方案。

The magnetron sputtering and photolithography is used for the fabrication of a film-planar-gate field emission arrays （FEAs） on the glass substrate. CNTs were migrated on the cathode electrodes of the film-planar-gate structure by electrophoretic deposition. The images of FEAs were investigated by optical microscope and scanning electron microscope （SEM）. The dis- tributions of the electric field near the cathode electrodes were simulated by Ansys, whose struc- ture parameters are optimized and field emission characteristics are discussed. The results showed that CNTs could be uniformly distributed on the surface of cathode electrodes. The maximum an- ode current density of film-planar-gate triode with CNTs emitters is 1.8 mA/cm2, the highest lightness was approximately 3 000 cd/m2 when gate voltage was 275 V and anode voltage was 2 400 V. Moreover, the uniformity was more than 90% and the emission current fluctuation was less than 5% for 28 h. The film-planar-gate field emission back light unit （FE-BLU） has some advantages of simple structure, low cost, good uniformity and high lightness, providing a feasi- ble scheme for the new large area FE-BLU in LCD.