IMPROVEMENT OF THE RESPONSE TIME FOR ORGANIC PHOTODETECTORS BY USING DISPLACEMENT CURRENT

A new method is proposed to improve the response time of organic photodetectors by using displacement current. By inserting a transparent organic dielectric layer between the organic semiconductor active layer and the electrode the displacement current will be produced and replace the conduction current for current propagation, which will overcome the disadvantage of low carrier mobility of organic semiconductors. Under the irradiation of nanosecond pulse laser the rise time and fall time of the organic photodetector based on displacement current decrease 10% and 86%, respectively comparing to the conventional organic photodetector based on conduction current, which indicates the displacement current could renew the operation principle for high-speed organic photodetectors.