氧化鎵鋅奈米片光檢測器與場發射之光電特性分析

Photoelectrical and Field Emission Characteristics of GaZnO Nanosheets

林麟恩(Lin-En Lin)

指導教授 ： 楊勝州

國立虎尾科技大學/電機資訊學院/電子工程系碩士班/碩士(2014年)

摘要

本論文主要研究方向可分為兩個部分，第一部分是氧化鋅奈米片與氧化鎵鋅奈米片之物理特性比較，第二部分簡述製造氧化鎵鋅奈米片之光檢測器和場發射元件之應用。以上研究方向如下:
第一部分:氧化鋅奈米片與氧化鎵鋅奈米片之物理特性比較
首先在清洗好的玻璃基板上濺鍍一層氧化鋅晶種層，使用硝酸鋅和氫氧化鈉作為反應物，且加入硝酸鎵反應物，以低溫水溶液法成長二維氧化鋅奈米片狀結構。之後由SEM、XRD、TEM分析得知氧化鋅奈米片以及氧化鎵鋅奈米片平均厚度與平均高度相差不遠，且奈米片皆為單晶Wurzite結構。由EDS得知氧化鎵鋅奈米片中有鎵元素的存在。由PL顯示奈米片有兩個波峰，首先是短波長約380nm的紫外光吸收峰，尤其是在鎵摻雜後有更明顯的提升，其後是560nm的氧空缺與鋅間隙所引起的缺陷峰，在鎵摻雜之後有明顯的抑制。
第二部分:氧化鎵鋅奈米片光檢測器之研究
一個新穎的氧化鋅奈米片光檢測器，憑藉較大的表面體積比和奈米等級厚度的優點，將二維氧化鋅奈米片組裝成元件。利用波長為365 nm且偏壓1 V之紫外光進行測試，量測結果顯示氧化鎵鋅奈米片有較高的光暗電流比1.41×104，同時照光下的反應速度與未照光下的飽和時間常數是2.45s和4s在重複量測週期下具有重複性，且具有較佳的穩定性。

關鍵字

氧化鎵鋅 ； 奈米片 ； 水溶液法 ； 光檢測器 ； 場發射

並列摘要

In this work, the GaZnO nanosheet was grown on a glass substrate by using a low-temperature aqueous solution method. A GaZnO nanosheet metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) was also fabricated. It was found that the average length and thickness of GaZnO nanosheets were about 2.6 um and 20~30 nm, respectively. The EDS spectra implied that the Ga atom indeed adulterate into the ZnO crystal lattice. The ratio between the near band-edge emission (NBE) and the deep-level emission (DLE) intensities (INBE/IDLE) obtained by PL gradually decreased because the DLE intensity from the nanosheets gradually increased with increase in the atomic number of the dopants increasing. The photo-current and dark-current constant ratio of the fabricated PD were approximately 1.41×104 when biased at 1 V. The field-emission performance of GaZnO nanosheets can be enhanced by illumination UV light. It was found that the turn-on electrical field was reduced from 4.66 to 2.83 V/μm and the field enhancement factor was enhanced from 4037 to 6616.

並列關鍵字

GaZnO ； nanosheet ； aqueous solution ； photodetector ； field emission

參考文獻

[1]H. L. Hartnagel et al., 1995, “Semiconducting Transparent Thin Films”, published by Institute of Physics Publication, 17

[2]J. Lim, K. Shin, H. W. Kim and C. Lee., 2004, “Effect of annealing on the photoluminescence characteristics of ZnO thin films grown on the sapphire substrate by atomic layer epitaxy” Science and Engineering B107, 301

[3]Jeong et al.,2001,“Electrical and optical properties of ZnO thin film as a function of depostition parameters”,Solar Energy Materials & Solar Cells, Vol. 65, No. 37.

[4]B. M. Ataev et al., 1995,“Highly conductive and transparent Ga-doped epitaxial ZnO films on sapphire by CVD”, Thin Solid Films, Vol. 260, No. 19.

[5]Yi Zeng, Liang Qiao, Yifei Bing, Mao Wen, Bo Zou, Weitao Zheng, Tong Zhang, Guangtian Zou.,2012, “Development of microstructure CO sensor based on hierarchically porous ZnO nanosheet thin films”, Sensors and Actuators B: Chemical, 897-902.