The optical response of ZnO nanorods induced by oxygen chemisorption and desorption

• DOI: 10.1016/j.snb.2017.12.093
• Publication Date: 2017-12-24T01:17:57Z
• Authors: Sanjaya Brahma; Chi-Wei Yang; Chiu-Hsin Wu; Feng-Ming Chang; Tsung-Jhe Wu; Chien-Sheng Huang; Kuang-Yao Lo
• Keywords: Chemisorption; Nanorod; Ultraviolet photoelectron spectroscopy

Abstract We demonstrate a strategic approach to realize the oxygen chemisorption and desorption over ZnO nanorods (ZNRs) by second harmonic generation (SHG), X-ray photoelectron spectroscopy (XPS) and a strong correlation is established in order to illustrate the quality of the top surface properties. A detailed investigation is carriedout with the variation of annealing temperature and oxygen flow rate for the optimization of the oxygen adsorption/desorption behavior. Oxygen species ionosorbed on ZNRs create a built-in electric field beneath the surface of ZNRs at room temperature and this directly reflects on the changes in the electric field induced SHG. The trend of decrease/increase in the intensity of SHG due to Ultraviolet irradiation and under rich oxygen atmosphere depends strongly on the quality of ZnO surface after post-annealing treatment. SHG is used extensively to indicate the dynamic chemisorption and desorption of oxygen on ZNRs in ambient atmosphere, which can assist the related research of oxygen adsorption in XPS under high vacuum.