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Single nanowire-based UV photodetectors for fast switching.

Ul Hasan K, Alvi NH, Lu J, Nur O, Willander M - Nanoscale Res Lett (2011)

Bottom Line: Desorption and re-adsorption of much smaller number of oxygen ions at the Schottky junction effectively alters the barrier height resulting in a faster response even for very long NWs.The photodetector shows high stability, reversibility, and sensitivity to UV light.The results imply that single ZnO NW Schottky diode is a promising candidate for fabricating UV photodetectors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Science and Technology (ITN) Linköping University, Campus Norrköping, SE-601 74 Norrköping, Sweden. kamran.ul.hasan@liu.se.

ABSTRACT
Relatively long (30 µm) high quality ZnO nanowires (NWs) were grown by the vapor-liquid-solid (VLS) technique. Schottky diodes of single NW were fabricated by putting single ZnO NW across Au and Pt electrodes. A device with ohmic contacts at both the sides was also fabricated for comparison. The current-voltage (I-V) measurements for the Schottky diode show clear rectifying behavior and no reverse breakdown was seen down to -5 V. High current was observed in the forward bias and the device was found to be stable up to 12 V applied bias. The Schottky barrier device shows more sensitivity, lower dark current, and much faster switching under pulsed UV illumination. Desorption and re-adsorption of much smaller number of oxygen ions at the Schottky junction effectively alters the barrier height resulting in a faster response even for very long NWs. The NW was treated with oxygen plasma to improve the switching. The photodetector shows high stability, reversibility, and sensitivity to UV light. The results imply that single ZnO NW Schottky diode is a promising candidate for fabricating UV photodetectors.

No MeSH data available.


Related in: MedlinePlus

Photoresponse of a single ZnO nanowire Schottky diode under pulsed illumination after oxygen plasma treatment.
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Figure 5: Photoresponse of a single ZnO nanowire Schottky diode under pulsed illumination after oxygen plasma treatment.

Mentions: The NW was then treated with oxygen plasma under an oxygen flow rate of 100 sccm, chamber pressure of 150 mTorr for 1 min. Photocurrent was observed to decrease after the oxygen plasma treatment but photocurrent rise and fall time under UV exposure is further improved significantly as compared to the untreated ZnO NW, as shown in Figure 5.


Single nanowire-based UV photodetectors for fast switching.

Ul Hasan K, Alvi NH, Lu J, Nur O, Willander M - Nanoscale Res Lett (2011)

Photoresponse of a single ZnO nanowire Schottky diode under pulsed illumination after oxygen plasma treatment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211437&req=5

Figure 5: Photoresponse of a single ZnO nanowire Schottky diode under pulsed illumination after oxygen plasma treatment.
Mentions: The NW was then treated with oxygen plasma under an oxygen flow rate of 100 sccm, chamber pressure of 150 mTorr for 1 min. Photocurrent was observed to decrease after the oxygen plasma treatment but photocurrent rise and fall time under UV exposure is further improved significantly as compared to the untreated ZnO NW, as shown in Figure 5.

Bottom Line: Desorption and re-adsorption of much smaller number of oxygen ions at the Schottky junction effectively alters the barrier height resulting in a faster response even for very long NWs.The photodetector shows high stability, reversibility, and sensitivity to UV light.The results imply that single ZnO NW Schottky diode is a promising candidate for fabricating UV photodetectors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Science and Technology (ITN) Linköping University, Campus Norrköping, SE-601 74 Norrköping, Sweden. kamran.ul.hasan@liu.se.

ABSTRACT
Relatively long (30 µm) high quality ZnO nanowires (NWs) were grown by the vapor-liquid-solid (VLS) technique. Schottky diodes of single NW were fabricated by putting single ZnO NW across Au and Pt electrodes. A device with ohmic contacts at both the sides was also fabricated for comparison. The current-voltage (I-V) measurements for the Schottky diode show clear rectifying behavior and no reverse breakdown was seen down to -5 V. High current was observed in the forward bias and the device was found to be stable up to 12 V applied bias. The Schottky barrier device shows more sensitivity, lower dark current, and much faster switching under pulsed UV illumination. Desorption and re-adsorption of much smaller number of oxygen ions at the Schottky junction effectively alters the barrier height resulting in a faster response even for very long NWs. The NW was treated with oxygen plasma to improve the switching. The photodetector shows high stability, reversibility, and sensitivity to UV light. The results imply that single ZnO NW Schottky diode is a promising candidate for fabricating UV photodetectors.

No MeSH data available.


Related in: MedlinePlus