无机纳米杂化聚酰亚胺中电荷陷阱分布的测量

Measuring the distribution of charges trapped in a hybrid nano polyimide film

为了研究纳米颗粒在聚酰亚胺材料中的作用,利用热激退极化电流方法测量了无机纳米杂化聚酰亚胺薄膜中电荷陷阱的分布.实验表明在495K左右,聚酰亚胺样品存在一个很宽的热激电流峰,估算了实验样品中电荷陷阱的能级分布在0.45～0.75eV.比较了经SiO2和Al2O3纳米杂化聚酰亚胺试样和原始聚酰亚胺试样的电荷陷阱分布情况,发现无机纳米掺杂物的加入明显使材料中的电荷陷阱密度增加.这可能是无机纳米复合聚酰亚胺薄膜耐电晕性能提高的原因之一.同时还发现,SiO2无机纳米复合聚酰亚胺的陷阱能级密度大于Al2O3无机纳米复合聚酰亚胺,说明在聚酰亚胺材料中,SiO2纳米颗粒比Al2O3更有效地引入电荷陷阱.

In order to study the effects of inorganic nano-particles in polyimide（PI）,its charge trap distribution was investigated by analyzing its thermally stimulated depolarization current（TSDC）.A broad TSDC peak was observed around 459 K in PI.The charge trap levels were estimated to be in the range of 0.45 ～0.75 eV.The trap distributions of PI-SiO2 and PI-Al2O3 nano hybrid films were compared.It was found that inorganic nano-particles can increase trap intensity in a film and the trap intensity of PI-SiO2 is larger than that of PI-Al2O3.This shows that SiO2 induces charge traps more efficiently than Al2O3 particles.The trap levels may be trapping electrons coming from corona discharges and preventing the PI film from the corona.This is one possible reason for nano-hybrid PI films having the property of corona-resistance.