A new method for direct determination of trap level distribution from TSC measurement

Thermally stimulated current (TSC) is developed and a new method for direct determination of trap level distribution in polymer film is proposed. In this method, a new function is defined to weight the contribution of a trap level to the current at any temperature. The demarcation energy is used to study the trap empty process. Analysis shows that only electrons with trap levels very close to the demarcation energy significantly contribute to the external circuit. Based on this method, the trap level distribution of polyimide is investigated. Experiments found that a broad peak appeared at about 440 K on TSC spectrum. The trap level distribution exhibits a density peak at about 1.35 eV. This is in accordance with the theoretical analysis by the proposed method which shows that only electrons with trap levels close to 1.3 eV contribute to the current at 440 K around.