基于CGSim模拟的炉膛空气对流对碲锌镉晶体生长温场影响研究  

Effect of Furnace Air Convection on the Temperature Field of Tellurium Zinc Cadmium Crystal Growth Based on CGSim Simulation

作　　者：马启司 刘江高 折伟林[1] 曹聪 张立超 赵超[1] 范叶霞 周振奇 MA Qisi;LIU Jianggao;SHE Weilin;CAO Cong;ZHANG Lichao;ZHAO Chao;FAN Yexia;ZHOU Zhenqi(The 11th Research Institute of China Electronics Technology Group Corporation,Beijing 100015,China)

机构地区：[1]中国电子科技集团公司第十一研究所,北京100015

出　　处：《人工晶体学报》2024年第8期1344-1351,1360,共9页Journal of Synthetic Crystals

摘　　要：碲锌镉晶体生长周期长、生长体系复杂,采用垂直布里奇曼法或者垂直温度梯度法生长碲锌镉(CdZnTe)晶体材料时,晶体的生长过程往往无法直观观察,晶体内部的温场也缺乏相应的手段检测,这对改进晶体生长工艺带来了诸多不便。利用计算机仿真能够将晶体生长的过程重构或再现。本文利用数值模拟软件,在晶体生长炉模型顶部塞子和底部塞子中心开孔,通过调节孔径大小(20~40 mm),对炉膛内气体的对流行为进行了规律性的调控。开孔前,炉膛内气体流速极低(只有10^(-5) m/s),形成流动缓慢、形状稳定的对流胞;开孔后,炉膛内气体流速明显增加(0.25~0.90 m/s),流动状态变为层流。通过控制模型的孔径大小,可以有效改变炉膛内气体层流的流速,相同温度设定下,流速从0.25 m/s增加到0.90 m/s时,温度梯度将从0.5 K/mm增加到1.1 K/mm。在实际空炉上进行开孔测温实验,验证了模拟结果中温度梯度变大的结论。通过监控炉膛内温度随时间的变化,发现层流模式下提高流速,有利于减小炉内温度随时间的波动,提高温场稳定性。温场温度梯度的增加和稳定性的提升,将有利于高质量碲锌镉晶体的制备。The growth cycle of tellurium zinc cadmium crystals is long and the growth system is complex.When using vertical Bridgman or vertical gradient freezing methods to grow tellurium zinc cadmium(CdZnTe) crystal materials,the growth process is often difficult to observe intuitively,and there is no corresponding means to detect the temperature field inside the crystals,which brings inconvenience to improve the crystal growth process.In this paper,numerical simulation software is used to analyze the influences of furnace air convection on the temperature field of CdZnTe crystal growth.By opening holes at the top and bottom of furnace,gas exchanging occurs between the inside and outside of the furnace,thereby regulates the convection behaviors.Before opening holes,the convection rate is slow(only 10^(-5) m/s),forming stable convection cells;after opening holes,the convection rate significantly increases(0.25~0.90 m/s),and the convection state changes to laminar flow.Through controlling the aperture size(20~40 mm) in the model,the laminar flow rate can be effectively regulated.At the same temperature setting,when the flow rate increases from 0.25 m/s to 0.90 m/s,the temperature gradient will increase from 0.5 K/mm to 1.1 K/mm.Furthermore,experimental work is applied on real furnace,the change of temperature filed before and after opening holes were studied.The experimental results of temperature gradient is accord with the simulating results.It is also found that under laminar flow state,increasing convection rate may improve the stability of temperature field.The increase of temperature gradient and the improvement of stability in the temperature field will be beneficial for the preparation of high-quality CdZnTe crystals.

关 键 词：碲锌镉 晶体生长 对流 温场 CGSim软件模拟 

分 类 号：O734[理学—晶体学]