本次實驗主要分為三大部分：（一）透過簡單、低成本、非真空的液相沉積法（LPD）製備β-Ga2O3奈米晶粒，作者首先利用硝酸鎵與碳酸鈉來調配出生長前驅物羥基氧化鎵（GaOOH）的化學溶液，並且透過調控溶液的成長溫度、時間和pH值，研究晶粒的形貌變化。作者成功透過退火工藝在800°C下經過3小時高溫煅燒，使得GaOOH轉變為β-Ga2O3；（二）利用β-Ga2O3寬能隙半導體的特性製備溫度感測器，作者透過水平結構的Ni/β-Ga2O3蕭特基二極體來進行變溫量測，其測量溫度範圍為100〜800 K。在室溫時，蕭特基能障為0.915 eV、理查生常數（Richardson’s constant）為43.04±0.01 A/cm2K2。並且觀測到靈敏度最高的地方位於300〜500 K的範圍區間，其輸入電流在10 A時達到-2.924±0.031 mV/K。由上述結果表明，透過LPD製備的β-Ga2O3有望成為高溫電子設備的潛力；（三）使用SolidWorks （3D電腦輔助設計軟體）搭配Ni/β-Ga2O3蕭特基二極體製備應變規（Strain gauge），並透過壓阻效應（piezoresistive effect）探討當β-Ga2O3受到應力時所產生的電阻變化。作者依照其受到應變時所產生的靈敏度來計算出其應變係數（Gauge Factor, GF），在位移0〜3 mm範圍之間，其GF值為-4.111±0.327。這些結果表明，LPD合成的β-Ga2O3材料在溫度感測器的高溫應用或是應變規的壓力測試中均具有廣闊的發展前景。

The thesis is mainly divided into three parts. The first part we report the synthesis of β-Ga2O3 nanocrystalline grains using a simple, low-cost, non-vacuum liquid phase deposition (LPD) method. We first used gallium nitrate (Ga(NO3)3) and sodium carbonate (Na2CO3) to produce a chemical solution of the growth precursor gallium oxyhydroxide (GaOOH). The morphological evolution of the grains was investigated by adjusting the growth temperature, time, and pH value of the solution. We successfully calcined gallium oxide hydroxide (GaOOH) through a 3-hour annealing process at 800°C to convert it into β-Ga2O3.
The second part we fabricated horizontal-structured Ni/β-Ga2O3 Schottky diodes and investigated the electrical characteristics relevant to sensing temperature in the range of 100 - 800 K. The temperature sensitivity of the Ni/β-Ga2O3 Schottky-junction temperature sensors, defined as the temperature dependence of junction voltage at a fixed bias current of 10 A, peaked at -2.924±0.031 mV/K in the range between 300 and 500 K. At room temperature, we measured a barrier height of 0.915 eV and a Richardson’s constant of 43.04±0.01 A/cm2K2 from the Ni/β-Ga2O3 Schottky junctions.
The final part we used SolidWorks (3D Computer Aided Design software) with Ni/β-Ga2O3 Schottky diodes to produce strain gauge, and we used the piezoresistive effect to investigate the resistance variety when β-Ga2O3 was strained. We calculated its gauge factor (GF) according to its sensitivity when subjected to strain. According to the experimental results, the GF value was -4.377±0.179 when the displacement was between 0 and 3 mm. These results indicate that the LPD-synthesized β-Ga2O3 material holds promising potential for high-temperature applications and strain gauge.

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