UV photocurrent responses of ZnO and MgZnO/ZnO processed by atmospheric pressure plasma jets

This paper reports the 368-nm UV photocurrent responses of rf-sputter-deposited ZnO and MgZnO/ZnO metal-semiconductor-metal photodetectors (MSM PDs) treated using atmospheric pressure plasma jets (APPJs). In ZnO and MgZnO/ZnO PDs, the dark current and photocurrent levels, photoresponsivities, and photocurrent response times in the fast rising and decay transition regions increase with the APPJ treatment duration. The MgZnO capping layer also increase the dark current and photocurrent levels, photo-responsivity, and fast decay transition time. These observations can be attributed to the shielding of ambient oxygen, defect and surface states passivation, and introduction of highly conductive interfaces at the MgZnO/ZnO heterojunctions. (C) 2014 Elsevier B.V. All rights reserved.