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0957-K07-28

A Solution Method for Large-Scale Selective Growth of Aligned ZnO Nanorods Qurashi Ahsanulhaq, Ahmad Umar, Sang Hoon Kim, Yeon Ho Im, and Yoon Bong Hahn School of Chemical Engineering and Technology, Chonbuk National University, Duckjin-Dong 1G, Jeonju, 561-756, Korea, Republic of

ABSTRACT (Example D) A facile and convenient aqueous route has been employed to synthesize high -aligned ZnO nanorods. Field emission scanning electron microscopy studies of ZnO nanorod arrays grown at 70ºC on ZnO/Si substrates show fine homogeneous surface. The average diameter of ZnO nanorod is in between 50-60 nm .The length of each nanorod is about 400 to 500 nm. Structural analysis showed that the ZnO nanorods are single crystalline with wurtzite hexagonal phase. Room temperature photoluminescence spectra of the ZnO nanorod arrays exhibit ultra violet emission and green emission. In addition, selective growth of ZnO nanorods on patterned ITO glass substrate is obtained. Each nanorod has diameter of 50 to 70 nm and their length upto 500nm. XRD pattern shows that ZnO nanorods on patterned ITO substrate are single crystalline in nature with wurtzite hexagonal phase. The room temperature photoluminescence from the aligned ZnO nanorods showed a strong ultra violet emission at 378 nm and broad deep level visible emission at 580 nm. INTRODUCTION (Example D) Zinc oxide (ZnO) has attracted much attention due to its unique physical properties and potential for diverse electronic and photonic applications. ZnO has direct band gap (3.37 eV), and large exciton binding energy of ~60 meV. Such properties suggest promising application of ZnO nanomaterial in short wavelength optoelectronic devices, ultraviolet (UV) lasers, sensors, energy conversion and storage (photovoltaic cells, hydrogen storage devices) and light emitting display etc. [1-8]. The physical properties of ZnO nanomaterials strongly depend on their dimensions and morphologies. Among 1D ZnO nanomaterial, aligned nanorods and nanowires exhibits particular performance which differs from that of spherical, discoid, flower, and other diverse morphologies and highly oriented, aligned and ordered arrays is of critical importance for the development of novel devices [9]. Among the various techniques reported in the literature, vapor-phase-deposition techniques are the most popular for high-temperature growth of highquality aligned ZnO nanorods. Even though this method can produce good quality aligned ZnO nanostructures, it is high energy consuming approach needs costly equipments and exigent experimental conditions. Due to such complexities solution phase synthesis (bottom-upapproach) came into existence, which proved promising due to its low temperature, versatile synthetic process. Here, we report a growth of well-aligned ZnO nanorods on ZnO/Si substrate and selective growth of ZnO nanorods on prepatterned ITO glass substrate by low temperature solution method. The structural and optical properties addressed in details.

EXPERIMENTAL DETAILS (Example D) The growth of ZnO films