MSM UV photodetector ZnO thin film MgZnO/ZnO heterostructure rf-sputtering Atmospheric pressure plasma jet UV responses a b s t r a c t 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 treat-ment 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. Ó 2014 Elsevier B.V. All rights reserved.