Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Persistent Photoconductivity Studies in Nanostructured ZnO UV Sensors | Nanoscale Res Lett 2009 4 1421-1427 DOI s11671-009-9414-7 NANO EXPRESS Persistent Photoconductivity Studies in Nanostructured ZnO UV Sensors Shiva Hullavarad Nilima Hullavarad David Look Bruce Claflin Received 8 April 2009 Accepted 7 August 2009 Published online 28 August 2009 to the authors 2009 Abstract The phenomenon of persistent photoconductivity is elusive and has not been addressed to an extent to attract attention both in micro and nanoscale devices due to unavailability of clear material systems and device configurations capable of providing comprehensive information. In this work we have employed a nanostructured nanowire diameter 30-65 nm and 5 m in length ZnO-based metal-semiconductor-metal photoconductor device in order to study the origin of persistent photoconductivity. The current-voltage measurements were carried with and without UV illumination under different oxygen levels. The photoresponse measurements indicated a persistent conductivity trend for depleted oxygen conditions. The persistent conductivity phenomenon is explained on the theoretical model that proposes the change of a neutral anion vacancy to a charged state. Keywords Persistent photoconductivity Semiconducting II-VI materials Zinc oxide UV sensor Nanoscale device Introduction The synthesis methods and the use of nanostructures for various applications have been a very lucrative topic in the last decade 1 . These efforts have lead to discoveries of S. Hullavarad El N. Hullavarad Office of Electronic Miniaturization University of Alaska Fairbanks AK 99701 USA e-mail D. Look B. Claflin Semiconductor Research Center Wright State University Dayton OH 45435 USA unknown phenomena and or new approaches to explain with precision the observed experimental and theoretical facts from the macro micro world 2 . When all is said and done the issues in nano-sized devices individual or arrays and basic impediments in device operation have not been addressed largely due to
