The structural and optical properties of Volmer-Weber-type ZnO nanorods

✍ Scribed by Park, Se-Jeong ;He, Weizhen ;Qiu, Jijun ;Kim, Jin Woo ;Lee, Ik Jae ;Kim, Beomkeun ;Kim, Hyung-Kook ;Hwang, Yoon-Hwae

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 510 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201000054

✦ Synopsis

Abstract

Volmer–Weber‐type ZnO nanorods (VW ZnO NRs) were fabricated by using a hybrid method combined with RF sputtering and hydrothermal methods. The structural and optical properties of VW ZnO NRs were investigated by using synchrotron X‐ray diffraction (XRD), micro‐Raman spectroscopy, photoluminescence (PL) spectroscopy and X‐ray photoelectron spectroscopy (XPS). It was found that VW ZnO NRs showed wurtzite structure and were vertically standing on a substrate with a compressive stress from the substrate that can be reduced by annealing. In the micro‐Raman study, a forbidden E~1~(LO) mode in a bulk ZnO was observed in VW ZnO NRs due to the many edges in NR structures. It was also confirmed that VW ZnO NRs have a wurtzite structure by observing E~2 low~ and E~2 high~ peaks. In the PL spectra, VW ZnO NRs showed a broad emission in the visible range, especially yellow emission, with a weak UV emission. The UV emission was monotonously enhanced on increasing the annealing temperature. The yellow emission was enhanced in the annealed sample at 200 °C due to an evaporation of hydroxyl groups (OH^−^) on the surface of VW ZnO NRs.