Evidence for Negative Electron Affinity in Laser Irradiated ZnTe Thin Films
In: Physical Science International Journal, Jg. 4 (2014-01-10), S. 657-668
Online
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Zugriff:
Local transport properties of laser irradiated ZnTe thin films are reported. By rastering the laser beam (of 532 nm wavelength) appropriately, ZnTe decomposes into n-type ZnTe and Te and a grating like struct ure with micro-stripesof ZnTe separated by grooves of Te is obtained. Conductive atomic force microscopy studies and local I -V measurements made on thestripesand grooves show that the film properties are mainly determined by chemical composition, ratherthan by the topography of the film. When the tip is positively biased, the current images closely match the topography images. In contrast, when the tip is negatively biased the current and topography images are very different and a large negative curren t was also observed in the grooves. This is attributed to the variation in charge separation (interface capacitance) caused by the rough surface. It is shown that Te forms ohmic contact with Au tip, but the junction exhibits Schottky diode behavior under l ow biasing voltages. The large current at both high positive and negative tip biasing may arise due to semi-metallic properties of Te. The I -V characteristics measurement reveals formation of Schottky barrier between ZnTe-Au junctions with a very low valu e (32.4 �78.3 meV) of barrier which indicates the presence of negative electron affinity . OriginalResearch Article
Titel: |
Evidence for Negative Electron Affinity in Laser Irradiated ZnTe Thin Films
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Autor/in / Beteiligte Person: | Kshirsagar, Sachin |
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Zeitschrift: | Physical Science International Journal, Jg. 4 (2014-01-10), S. 657-668 |
Veröffentlichung: | Sciencedomain International, 2014 |
Medientyp: | unknown |
ISSN: | 2348-0130 (print) |
DOI: | 10.9734/psij/2014/5907 |
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