Enhancement of the Photo-Response Properties of the Flexible CdS Films by an Application of Electrical Field

Photo-response switching of the CdS films grown at an optimum condition for the photo-sensor applications was investigated by an application of the electrical field. Recovery to the original dark-resistance after a light-off was achieved for 60 s by an application of the electrical field (∼30 V) in the two electrodes structure. On the other hand, in the structure of three electrodes, after application of −10 V for microsecond at third electrode at a light-off state, the dark-resistance was recovered to its original value for three second. An application of the negative electrical field in the three electrodes structure remarkably improved the switching characteristics of the photo-response of the CdS films.