以垂直布氏長晶法生長GaSe晶體及特性量測

Abstract

本研究是以垂直布氏長晶法生長GaSe晶體，從X-Ray繞射中知道我們生長出的晶體屬於相的GaSe。在生長的過程中我們加入過量的Se以避免因揮發而造成的不足。同樣地，我們嘗試使用Se為氣氛，以不同溫度做72小時熱處理。分別以X-Ray的半高寬值，10m中紅外光之吸收係數，室溫PL螢光的強度，低溫PL（70K）的本質螢光強度與非本質的螢光強度比做比較，發現在生長時加入過量5％Se時會得到較好品質的晶體。經過600oC，加入5% Se的氣氛做熱處理後，會改善晶體品質及減少的雜質和缺陷的存在，得到所有試片中品質最好的晶體。

In this study ,crystals of GaSe were grown by Vertical Bridgeman method .An X-Ray diffraction pattern showed that crystal belong to -modification .Since Se evaporate well below the melting point of GaSe (938oC) , an excess of Se was added in the synthesis procedure . The influence of synthesis procedure on sample quality would be examined by X-Ray , absorption coefficient , and PL . Annealing of as-grown GaSe crystals in different Se atmosphere at 500oC,600oC and 700oC for 72 hours took a decrease of intrinsic defects of gallium vacancy .The influence of annealing procedure on crystal quality would also be examined . The result showed that , an excess of Se for 5wt% had better quality in the procedure of crystal growth . Our investigation of annealing at different temperature and atmosphere showed that the condition in 5wt% Se atmosphere at 600oC were optimal for the reduction in the number of intrinsic structure defects .