砷銻氮化鎵之材料特性與光電元件研究

Abstract

本論文的研究主題為熱退火對砷銻氮化鎵化合物半導體材料特性的影響以及利用砷銻氮化鎵化合物製作長波長光偵測器與太陽能電池。在砷銻氮化鎵塊材的研究中，我們發現在當氮含量超過1.7%時，矽與鈹等加入雜質有被鈍化的現象。雖然熱退火能改善光激螢光頻譜強度並且減少元件的漏電流密度，但也會提高電洞密度並造成導電型態轉換為P型。我們將這種現象歸因於熱退火所產生的受子型缺陷。在元件的研究方面，我們利用比較的方式發現異質結構、N-on-P型結構的元件最能適應熱退火所造成的導電型態轉換。接著，我們以此結構對熱退火的時間與溫度作詳細的最佳化研究。我們發現低溫長時間的熱退火條件不僅能獲得較好的光激發螢光強度而且有較低的受子型缺陷。最後，我們利用異質結構、N-on-P的元件結構製作截止波長超過1600 nm的光偵測器以及轉換效率達3.64%的1-eV太陽能電池。

We have studied the effect of thermal annealing on the properties of GaAsSbN and the fabrication of GaAsSbN PIN devices. Passivation of Si and Be dopants in as-grown GaAsSbN was observed when the composition of nitrogen exceeded 1.7%. Although thermal annealing can improve the photoluminescence intensity and decrease the leakage current of the PIN junction, it results in high hole concentrations, leading to the conduction-type conversion in un-doped and Si-doped GaAsSbN. This phenomenon is ascribed to the generation of acceptor-type defects during the annealing process. After a comparative study on the device structures, we found that the N-on-P hetero-junction device has the best immunity to the type conversion effect resulting from the annealing process. Then, the effect of annealing temperature and duration on the device performance was systematically investigated. We found that annealing at 650