聚合物电介质薄膜的能量归一化光激电流谱

Energy normalized photon-stimulated discharge spectra of polymer dielectric film

为了利用光激电流谱准确地表征聚合物电介质材料中的电荷陷阱密度按能量分布的情况，需要将原始光激电流谱对光激发能量进行归一化。依据光激电流强度与陷阱电荷释放量以及激发光强的关系，给出了能量归一化光激电流谱的定义及其测量原理。根据这一原理设计了实际的测量系统，该系统由波长可调谐的激光器、光能量计、静电计和测试样品室构成。系统由基于LabVIEW开发的软件控制，实现激发光波长的线性扫描和电流与光能量信号的实时采集。利用该系统测量了聚酯薄膜的能量归一化光激电流谱，测量结果发现在聚酯薄膜中电荷陷阱能量主要分布在4．08～5．17eV之间，在4．22eV处具有陷阱态密度最大值，并计算出该能量附近的电荷陷阱密度为5×10^14cm^-3数量级。

In order to characterize accurately the distribution of charge traps on energy in polymer dielectric materials by using Photon-stimulated Discharge（PSD） Spectra, the raw PSD Spectra need to be normalized by the energy of light excitation. The definition of energy normalized PSD Spectra and a practical measurement system are given by analyzing the relation of PSD current, changing from traps and light intensity. The principle of the measurement system is discussed as well composed. The system is composed of a wavelength tunable laser, an optical energy meter, an electrometer and a specimen chamber. The system is controlled by software based on LabVIEW to achieve a linear scan of excitation wavelength and a real-time acquisition of current and light energy. A normalized energy PSD Spectra of Polyethylene Terephthalate （PET） film was measured using the system. It shows that the energy of charge traps in the PET film is mainly distributed in 4. 08 -5.17 eV, and there is a maximum at 4. 22 eV. The magnitude scale of the density of traps near the maximal energy is estimated as about 5 ×10^14cm^-3.