以垂直式布氏長晶法生長未摻雜及鍺摻雜AgGaS2單晶

Abstract

直式布式長晶法生長出直徑達1.1公分，長度在3－5公分的純的 aS~\2~Z 單晶。單晶生長所使用的原料是在高溫直接合成；也就是將銀、 、硫、 鍺)元素置於真空石英管中，在高溫搖混爐中合成AgGaS~\2~Z的 蝐敦Q□ 配料成份、□原料合成溫度、□熔液╱固體界面之溫度梯度、□ 劃犑峈 活B□冷卻過程等對AgGaS~\2~Z單晶生長之影響。我們發覺以多加1硫的複 晶原料及34╱液體界面溫度梯度較易長出大晶體，若以未加過量硫的原料 及34梯度進行長晶則長不出大體積的晶體。合成原料的溫度在1000 ℃ ∼1100所合成出的原料成份皆大致均勻並無明顯的差別。在0.75 cm/day 及2.8像t率對單晶 獐v響。長晶管的形狀及長晶後的降溫過程對晶體的成 長影響亦不大，我們 @狀或球狀，長晶管前端約1公分處皆長出複晶。 降溫時氣相中過飽和的硫□ 銂磾悸漯R出物。我們建議的長晶條件為： 合成原料：多加1鴟こ贖蛂G 1050 ℃，熔液╱固體界面的溫度梯度34 ℃/ cm，拉昇速率：2.8G前端圓錐狀或球狀皆可，降溫方式： 24小時降至室 溫。 曭獐v響不大，上述的長晶的條件適用於純的AgGaS~\2~Z以及Ge摻雜 的 ped的單晶其外形狀及色澤與un-doped的單晶並無明顯差異。由EPMA的 結果 AAg、Ga、S三元素的成份分佈皆很均勻。在摻雜鍺之晶體中其鍺 的濃度約她ms/cc左右， 芘捸C由單晶中的Ge含量與配料中Ge含量的比值 可得出Ge在固體及熔液中的為0.40∼0.47(配料濃度1×10~^19~Z Ge7 ∼0.039(配料濃度1×10~^20~Z Ge atoms/cc)。在純的 擗仇□[測到析出 物及雙晶兩種缺陷。析出物可在高溫以及高的硫蒸氣壓下氣壓硫磺蒸氣 壓)經長時間熱處理而消除。 P雙晶之間的關係我們認為雙晶係形成於析 出物之前。兩條雙晶的交會處常存在顯示它們應為變形雙晶而非成長雙晶 。 Undoped and Ge-doped AgGaS~\2~Z single crystals of diameters up for applications in nonlinear optics and blue light emittingn successfully grown by vertical Bridgman method. The source the single crystal growth were directly synthesized at high (>1050℃) using elemental Ag, Ga and S (or Ag, Ga, S and Ge). the high temperature melt is enhanced by mechanical rocking. The several growth parameters on the crystal growth werehese include (1) composition of the charge materials, (2) synthesizing (3) the temperature gradient at the melt/solid interface, (4)5) the shape of the growth ampoule, and (6) the cooling schedule. that large size, high quality crystals can be grown by using 1 sulfur in the original charge and a temperature gradient of combination of stoichiometric charge (no excess sulfur) and a gradient of lower than 34 results in poor quality growth. The synthesizing temperature between 1000 to 1100℃ has little effect single crystal grown. Pulling rate between 0.75 and 2.8 cm/day similar results. The electron probe microanalysis (EPMA) results indicate that the distribution of Ag, Ga, and S are fairly uniform in the as-grown both undoped and doped cases. Irrespective of the Gen the Ge-doped melt, the level of the Ge incorporation in the as-grown about 4×10 ~^18~Z atoms/cc. Twins and Ga-rich precipitates are observed in both undoped and Ge-doped AgGaS2 singletates can be removed in high temperature under high sulfur vapor pressure (such as 950℃, 10 pressure).