tailieunhanh - Báo cáo hóa học: " W18O49 Nanowires as Ultraviolet Photodetector"

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: W18O49 Nanowires as Ultraviolet Photodetector | Nanoscale Res Lett 2010 5 416-419 DOI s11671-009-9499-z NANO EXPRESS W18O49 Nanowires as Ultraviolet Photodetector Feng Yang Kai Huang Shibing Ni Qi Wang Deyan He Received 26 October 2009 Accepted 16 November 2009 Published online 27 November 2009 The Author s 2009. This article is published with open access at Abstract Photodetectors in a configuration of field effect transistor were fabricated based on individual W18O49 nanowires. Evaluation of electrical transport behavior indicates that the W18O49 nanowires are n-type semiconductors. The photodetectors show high sensitivity stability and reversibility to ultraviolet UV light. A high photo-conductive gain of 104 was obtained and the photoconductivity is up to 60 nS upon exposure to 312 nm UV light with an intensity of mW cm2. Absorption of oxygen on the surface of W18O49 nanowires has a significant influence on the dark conductivity and the ambient gas can remarkably change the conductivity of W18O49 nanowire. The results imply that W18O49 nanowires will be promising candidates for fabricating UV photodetectors. Keywords W18O49 nanowires Field effect transistor Ultraviolet photodetector Photoconductive gain Near-surface depletion region Introduction Nowadays ultraviolet UV photodetectors play very important roles in many fields such as missile tracking ozone monitoring flame detection imaging techniques and lightwave communications 1-3 . One-dimensional nanostructures of high-performance oxides have attracted considerable attention as a class of potential optoelectronic materials. So far UV nano-photodetectors based on ZnO nanowires SnO2 nanowires and Ga2O3 nanowires have F. Yang K. Huang S. Ni Q. Wang D. He El School of Physics Science and Technology Lanzhou University 730000 Lanzhou China e-mail hedy@ 0 Springer been investigated and some remarkable characteristics such as wavelength selectivity and photoresponse have been revealed 4-7 . As a kind of important transition