ITO镀膜工艺对LED器件光电性能的影响

Effect of ITO Thin Film Coating Process on Optoelectronic Properties of LED Devices

通过电子束蒸镀和直流磁控溅射方法分别制备ITO薄膜,分析表面形貌和测试XRD图谱,对比ITO薄膜的成膜性、晶化程度、晶粒尺寸和晶面取向等的差异。发现磁控溅射的(222)晶面衍射峰强度比电子束镀膜的明显加强,磁控溅射的晶粒尺寸更大更均匀。将ITO薄膜分别应用到550um*760um GaN发光二极管中,小电流注入时,磁控溅射ITO的近场分布与电子束蒸镀TIO的近场分布差异较小,当电流密度超过7A/cm2后,磁控溅射的ITO横向扩散比电子束蒸镀的ITO好,整体近场分布较均匀;当电流密度超过23.5A/cm^(2)后,磁控溅射ITO的LED亮度提高,器件的过载能力比较强。

ITO thin films were prepared by electron beam evaporation and DC magnetron sputtering,respectively.The surface morphology and XRD patterns of ITO films were analyzed,and the differences of film formation,crystallization degree,grain size and crystal plane orientation were compared.It is found that the diffraction peak intensity of the(222)crystal plane of magnetron sputtering is obviously stronger than that of electron beam coating,and the grain size of magnetron sputtering is larger and more uniform.When ITO thin films are applied to 550um*760um GaN light emitting diode(LED),if low current is injected,the near field distribution of magnetron sputtering ITO is smaller than that of electron beam evaporated ITO.When the current density exceeds 7A/cm^(2),the transverse diffusion of magnetron sputtered ITO is better than that of electron beam evaporated ITO,and the overall near field distribution is more uniform.When the current density exceeds 23.5A/cm^(2),the LED brightness of magnetron sputtered ITO is improved,and the overload capacity of the device is strong.