本實驗首先分別探討氯化鎵及氧化砷在60.0/40.0 mol% AlCl3-MeEtimCl室溫融鹽的電化學行為,所選用的工作電 極為鎢,得知三價鎵在此融鹽中還原是先獲得兩個電子,再獲得一個電子 還原到元素態鎵,此兩步驟的電化學反應皆為半可逆反應;而三價砷的還 原則一次獲得三個電子,還原至元素態砷,此步驟的電化學反應則為不可 逆反應.在析鍍砷,鎵方面,由於砷的還原電位在鎵之前,因此融鹽中氧 化砷的濃度要比氯化鎵低,經由能譜儀對鍍層分析,得知最符合砷/鎵= 1/1的溶液組成為:氯化鎵濃度0.02M,氧化砷濃度為其1/3( 即0.02x1/3),此時析鍍的電位為-0.01V.將析鍍所得之 樣品以X光繞射分析儀進行分析,發現並無砷化鎵晶型的訊號,經過25 0度C,鍛燒三小時後,再以X光繞射分析儀進行分析,則可得砷化鎵晶 型的訊號. The first part of this thesis di scussedthe electrochemistry beha vior ofgallium(III) oxide in the room-temperature molten salt. T unsten wasselected as the workin g electrodebecause of its electr ochemistry behavioris more obvio us than carbon,nickel,andcopper electrodes from cyclic voltammet ry experiments.In the electrodep osition section, sincethe reduct ion over potential of arsenicoxi de is less than gallium, the con centration of arsenic oxide is l owerthan gallium chloride at mol ten salts.In the experimental de sign, the concentration of galli um chloride wasvaried from 10mM to 50mM, which arsenideoxide was changed in the range of 1/2 to1 /5 of gallium chloride concentra tionFrom this experiment, the me lt contained20mM GaCl3 and 6.6mM (20/3mM)As2O3 is the better comp osition. The best sample waschar acterized by X-ray diffraction(X RD).According to the results of the X-raydiffraction, 3-hour ann ealing isrequired to get crystal line GaAs.
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