本論文利用三族氮化物中，具有紫外光至藍光吸收波段之氮化鎵材料研製光偵測器，可應用為紫外光或藍光感測器，並以GaN/InGaN多重量子井主動層結構製作PIN(p-intrinsic-n-type)光偵測器，探討其光電特性、響應率及量子效率。本論文在研製氮化鎵PIN光偵測器時，分別使用商用級氮化鎵晶圓與實驗級含有布拉格反射鏡(Distributed Bragg Reflector, DBR)之氮化鎵晶圓進行不同製程的探討。我們在DBR晶圓製作表面粗糙化，希望透過散射體的作用，增加主動區的光程長度，提升吸收效率與光電流。在商用級氮化鎵晶圓則是用本實驗室標準製程研製。
　　我們分別量測兩種不同結構元件的特性，使用商用氮化鎵晶圓所製作的光偵測器在AM1.5G光源量測下，有頗高的短路電流密度、開路電壓以及轉換效率，如此特性代表晶圓與製程品質是相當好的；使用IPCE量測並外加逆偏壓由0伏特增加至10.5伏特，其外部量子效率由36.57%增加至43.38%，在峰值波長385nm室溫下，對應的響應率則是113.3~134.4mA/W。
　　在DBR晶圓方面，雖然有著低的串聯電阻與在逆偏壓下無漏電情況，表示製程良好，但是在電致出光效率、開路電壓以及短路電流密度方面，皆有偏低的情況，因此磊晶DBR所產生的缺陷等問題需要去解決。

In this paper, we used III-nitride material having absorption bands in ultraviolet to blue light to make photodetectors that can be further engineered to be ultraviolet or blue light sensors. PIN (p-intrinsic-n-type) photodetectors were fabricated using epitaxial wafers with GaN/InGaN multiple-quantum-well active layer, and characterized in terms of optical and electrical characteristics, responsivity and quantum efficiency. In the development of GaN PIN photodetectors, we used commercial GaN wafers and laboratory-made GaN wafers containing distributed Bragg reflector (DBR) to study the performance. In addition, we roughened the surface of a DBR wafer to increase the optical path length in the active region via scattering to enhance the absorption efficiency and photocurrent. In contrast, the commercial GaN wafers were processed in accordance with our laboratory’s baseline procedures.

Photodetectors made of differently structured wafers were then characterized. The devices from commercial GaN wafers, measured by a standard 1-sun AM1.5G solar simulator, exhibited quite high short-circuit current density, open-circuit voltage and conversion efficiency indicating good quality in both wafer and processing. When measured by IPCE (Incident photon to electron conversion efficiency) system with a reverse bias increased from 0 to 10.5 volts, the external quantum efficiency at the peak wavelength of 385nm increased from 36.57% to 43.38% at room temperature, and the corresponding responsivity increased from 113.3 to 134.4mA / W.

For DBR wafers, although the devices have low series resistance and showed no leakage current under reverse bias, suggesting that the processing was good, the electroluminescence efficiency, open-circuit voltage and short-circuit current density were quite low. Therefore, the epitaxial DBR-caused defect problem needs to be resolved.

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