沉積於多晶矽之氧化鎵/氧化鋅之發光二極體

Abstract

本論文主要探討生長於多晶矽基板上的氧化鎵與氧化鋅二極體之製作以及其特性。第一部分為製成步驟以及沉積原理。第二部分為元件的電性與電致發光光譜量測。 元件的結構為ITO/NiO/Ga2O3/ZnO/ Ga2O3/ZnO/ Ga2O3/ITO。經由EDX、XRD等方式分析元件的元素比例以及晶性。自EDX可以得知元件的組成為氧化鎵、氧化鋅、以及ITO為主。XRD分析中得到氧化鋅的[h,k,l]= [0,0,2]，晶粒大小為25.33nm。 在元件電性與發光光譜的部分，元件的電流電壓特性除了呈現正常的二極體整流曲線外，在出現電壓崩潰後電流電壓特性出現了負微分電阻的現象。元件光譜的主要波長為500nm，隨著元件ITO厚度的不同，光譜也在不同的波長出現峰值。最後，對發光元件進行角度變化的量測。隨著量測角度的變化，光譜出現藍移，說明了人眼所觀察到的光色會隨著角度而有所影響。

This thesis mainly discussed the fabrication and the characterization of the gallium oxide- zinc oxide diode deposited on the polycrystalline silicon substrate. The first part of thesis was about the principles of the deposition equipment and the mechanism of deposition. The second part of thesis focused on the electrical and optical characterization of the devices. The structure of the device was ITO/NiO/Ga2O3/ZnO/Ga2O3/ZnO / Ga2O3/ITO. Energy dispersion X-ray spectrometer (EDX) and X-ray diffraction (XRD) were used to analyze the ratio of elements and the crystal orientation. From EDX measurement, the elements, gallium oxide, zinc oxide, indium tin oxide did exist in the device. The XRD measurement found that zinc oxide exhibits a preferred orientation of [h,k,l]=[0,0,2], with an average grain size of 25.33nm. In the chapter of electrical and optical measurements, the electric characteristic curve of the device showed a diode curve under forward bias. After a backward bias was applied, the curve exhibited a phenomenon of negative differential resistance under the second forward bias. The main wavelength on optical spectrum was 500nm. As the thickness of ITO changed, the variation of the peaks in spectrum were investigated. In the end, the angle-dependent electroluminescence was also investigated. As the measured angles increased, blue shifts were found in the spectrum, which explained the colors that human’s eyes observed would be influenced by observer’s angle.