前置晶種生長AgGa(SxSe1-x)2晶體與性質量測

Abstract

本研究以垂直布氏長晶法及長晶管前置晶種來生長AgGa(SxSe1-x)2晶體，x為0、0.25、0.5、0.75與1，並對此系列紅外線非線性晶體做X-Ray、EPMA、FTIR、OM、PL、Raman分析。長晶過程中，藉由控制生長速率、溫度梯度及前端置放晶種及控制液固接面位置，來克服晶體產生複晶、脆裂及氣泡等問題。我們得到藉由x比例的增加可增大能隙寬度，並獲得較小的a、c晶格常數，改變紅外光譜通光範圍由0.705~19.45μm偏向0.48~14μm，並在實驗中觀察到拉曼振動模式在四元固溶體內類似AgGaS2與AgGaSe2。

In this study，single crystals of AgGa(SxSe1-x)2，composition x varying from 0 to 1 with a 0.25 increase，was grown with seed by vertical Bridgman method. Using X-Ray、EPMA、FTIR、OM、PL、Raman spectrum these measurements，the characteristic properties of non-linear infrared crystal was obtained. The problems of micro-cracks、poly-crystal and air-bubble were overcomed by changing growth rate、temperature gradient、seed and the position of thermal couple. The higher energy band-gap、the lower lattice constant a and c have obtained by increasing composition of x. The infrared transmittance range is from 0.705~19.45μm toward 0.48~14μm. The Raman shift of AgGa(SxSe1-x)2 crystals are similar to these of AgGaS2 and AgGaSe2.