Synthesis, Optical Properties, and Ethanol-Sensing Properties of Bicone-like ZnO Microcrystals via a Simple Solution Method

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• 作者：Qingjiang Yu ; Cuiling Yu ; Wuyou Fu ; Mingxia Yuan ; Jin Guo ; Minghui Li ; Shikai Liu ; Guangtian Zou ; Haibin Yang
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：July 16, 2009
• 年：2009
• 卷：113
• 期：28
• 页码：12016-12021
• 全文大小：257K
• 年卷期：v.113,no.28(July 16, 2009)
• ISSN：1932-7455

文摘

Large-scale uniform bicone-like ZnO microcrystals were successfully synthesized via a simple solution method at lower temperature (80 °C). The as-prepared bicones, composed of two cones, possess a single-crystal hexagonal structure and grow along the [0001] direction. The influence of the reactant concentration on the size and shape of the ZnO samples has been studied in detail, and the results revealed that reactant concentration plays a crucial role in determining the final morphologies of the samples. The growth process of the bicone-like ZnO microcrystals was viewed by field emission scanning electron microscopy (FESEM) characterization, and a possible formation mechanism was proposed. Optical properties of the bicone-like ZnO microcrystals were also investigated by photoluminescence (PL) spectroscopy. The room-temperature PL spectrum of the bicone-like ZnO microcrystals shows a strong UV emission peak. The UV emission is further identified to originate from the radiative free exciton recombination by temperature-dependent PL. In addition, the bicone-like ZnO microcrystals exhibit excellent sensing properties toward ethanol gas at an operating temperature of 300 °C. The response and recovery times are 2 and 3 s, respectively. These results indicate that the bicone-like ZnO microcrystals have potential applications in fabricating optoelectronic devices and gas sensors.