AgGa_(0.2)In_(0.8)Se_2晶体小温度梯度生长与性质表征

Growth and Performance Characterization of AgGa_(0.2)In_(0.8)Se_2 Crystal under Low Temperature Gradient Condition

利用单温区机械振荡法合成出高纯单相AgGa_0．2In_0．8Se_2多晶，单次合成量超过400g；DSC测试结果显示其熔点为782℃，结晶温度为771℃。利用坩埚下降法在小温度梯度（2℃／cm）下生长出尺寸为φ25mm×75mm高品质无开裂AgGa_0．2In_0．8Se_2单晶。解离面（112）面摇摆曲线半峰宽为0．056°。厚度为3mm双面抛光的（112）面晶片在1．5～18μm波段透过率为65．0％～67．5％，表明所生长AgGa_0．2In_0．8Se_2晶体具有较低的吸收系数，为0．01～0．1之间。

More than 400 g of high-pure and single-phase AgGa_0.2In_0.8Se_2 polycrystalline was synthesized in one run by mechanical oscillation method in a single temperature zone furnace. The result of DSC analysis indicate that the melting and refreezing points of AgGa_0.2In_0.8Se_2 were 782 ℃ and 771℃, respectively. High-quality non-cracking crystal of AgGa_0.2In_0.8Se_2 with dimension of φ25 mm × 75 mm was grown by Bridgman method under a low gradient condition （2 ℃/cm）. The FWHM of the （112） peak rocking curve is about 0. 056° and the transmittance through a polished 3 mm thick （112） plate is 65.0%-457. 5% over the wide range of 1. 5-18 μm, which indicated the as-grown crystal has low absorption coefficient of 0. 01-0.1.