Photoresponse Properties of CdSe Single‐Nanoribbon Photodetectors |
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| Authors: | Y Jiang W?J Zhang J?S Jie X?M Meng X Fan S‐T Lee |
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| Affiliation: | 1. Center Of Super‐Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (P.R. China);2. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, Anhui (P.R. China);3. Nano‐Organic Photoelectronic Laboratory, Technical Institute of Physics and Chemistry, The Chinese Academy of Science, Beijing 100101 (P.R. China) |
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| Abstract: | Photodetectors are fabricated from individual single‐crystal CdSe nanoribbons, and the photoresponse properties of the devices are studied systematically. The photodetector shows a high sensitivity towards excitation wavelength with a sharp cut‐off at 710 nm, corresponding to the bandgap of CdSe. The device exhibits a high photo‐to‐dark current ratio of five orders of magnitude at 650 nm, and can function with excellent stability, reproducibility, and high response speed (< 1 ms) in a wide range of switching frequency (up to 300 Hz). The photocurrent of the device shows a power‐law dependence on light intensity. This finding together with the analysis of the light intensity‐dependent response speed reveals the existence of various traps at different energy levels (shallow and deep) in the bandgap. Coating with a thin SiO2 isolating layer increases the photocurrent but decreases the response speed of the CdSe nanoribbon, which is attributed to reduction of recombination centers on ribbon surface. |
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| Keywords: | Nanoribbons Photochemistry Photodetectors Photoresponsive materials |
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