Open-circuit voltage and short-circuit current characteristics of moisture absorbed polyimide thin films with different electrode materials

In this paper, we studied the open-circuit voltage (Vo) and short-circuit current (Is) of moisture absorbed polyimide (PI) thin films with different electrode materials in order to clarify their generation mechanism in terms of internal carrier movement in humid condition. Here the Vo and Is becomes large in humid condition. Since the electrical conduction of moisture absorbed PI may be of an ionic nature, PI with different electrode materials forms a galvanic cell and a electromotive force is generated by the chemical reaction at the metal-PI interface. The short-circuiting of sample and prestress levels affects the Vo properties. The short-circuiting time changes the value of the initial Vo and the time for Vo to arrive at its plateau. The polarity and level of prestressing also changes the Vo properties. These results are related to the distribution of internal carriers in sample