Title: Structural, optical and field emission properties of ZnO nanowires grown by non-catalytic thermal evaporation process

Authors: Ahmad Umar, S.H. Kim, M. Vaseem, J-H. Kim, Y.B. Hahn

Addresses: School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Chonbuk National University, 664-14 Duckjin-Dong 1-Ga, Chonju 561-756, Republic of Korea. ' School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Chonbuk National University, 664-14 Duckjin-Dong 1-Ga, Chonju 561-756, Republic of Korea. ' School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Chonbuk National University, 664-14 Duckjin-Dong 1-Ga, Chonju 561-756, Republic of Korea. ' School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Chonbuk National University, 664-14 Duckjin-Dong 1-Ga, Chonju 561-756, Republic of Korea. ' School of Semiconductor and Chemical Engineering, BK21 Centre for Future Energy Materials and Devices, Chonbuk National University, 664-14 Duckjin-Dong 1-Ga, Chonju 561-756, Republic of Korea

Abstract: Well-crystallised vertically aligned ZnO nanowires have been synthesised on silicon substrate via simple thermal evaporation process without the use of metal catalysis or additives at 750°C by using metallic zinc powder and oxygen gas as source materials for zinc and oxygen, respectively. The X-ray diffraction (XRD) pattern of the grown nanowires reveals that the grown structures are well-crystalline and possessing a wurtzite hexagonal phase. The room-temperature PL spectrum exhibited a sharp and strong UV emission with a broad green emission confirming good optical properties for the as-grown ZnO nanowires. The field emission characterisation exhibited that a turn-on field for the vertically aligned ZnO nanowires was 3.7 V/μm and the emission current density reached to 0.014 mA/cm² at an applied electrical field of ∼5.5 V/μm and shows no saturation. Moreover, the ZnO nanowire based field emission device exhibited a uniform light emission.

Keywords: II–VI semiconductors; zinc oxide; ZnO nanowires; thermal evaporation process; photoluminescence; field emission properties; optical properties; nanotechnology; structural properties.

DOI: 10.1504/IJNM.2009.028113

International Journal of Nanomanufacturing, 2009 Vol.4 No.1/2/3/4, pp.77 - 83

Published online: 07 Sep 2009 *

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