【作者】 陈俊；

【导师】 朱世富；

【作者基本信息】 四川大学 ， 凝聚态物理， 2006， 硕士

【摘要】 CdZnTe(CZT)是制作室温γ射线及X射线探测器的优良材料, CZT核辐射探测器具有较高的探测效率和较好的能量分辨率。在CdZnTe探测器的制备过程中,晶体的表面处理和钝化是影响其性能的重要因素。为此本论文针对CZT核辐射探测器制备关键工艺—表面处理和钝化工艺进行了研究。CZT晶体具有脆性,容易在外力作用下产生裂纹,以至破碎。因此,在CZT晶体的切割过程中,应控制进刀速度以及冷却水的温度,避免因速度太快而造成“裂纹层”。经过反复试验研究,选择1mm/min切割速度,厚度为2.5 mm,切得的晶片适合探测器制备。机械研磨CZT晶片,在压力一定的情况下,研磨速度至关重要,速度太慢,影响研磨效率;速度太快,会导致CZT晶片破碎、发热,并使机械运动的平稳性变差,磨出的CZT晶片的表面平整性较差,甚至导致晶片破损。经过实验研究发现,对CZT晶片采用研磨速度为40转/分较合适。经过机械抛光后的CZT晶片,肉眼看上起很平整、光亮,但在显微镜下观看其表面仍有许多划痕和不洁的斑点。采用溴甲醇(BM)和乳酸乙二醇溶液(LB)对CZT晶体进行表面化学抛光,BMLB化学抛光液可以有效去除样品表面机械抛光所引入的划痕,使得表面变的光亮平整。XPS能谱分析表明, CZT晶片经过机械抛光后,其表面为富镉原子层;经过化学抛光后,其表面层为富碲原子层,因此不论是机械抛光或是化学抛光都会破坏晶体表面的化学配比。更多还原

【Abstract】 CdZnTe(CZT) nuclear detectors have been widely utilized as x,γray detectors and image instruments for its high detection efficiency and good energy resolution. Since the performance of detectors is greatly influenced by the surface treatment and the passivation of the crystal, the main purpose of this thesis is to study the surface treatment and passivation processes of CZT nuclear radiation detector.CZT crystal with its brittleness is easy to produce crack or crash under the external force. So, during incising the CZT crystal, we should control the speed of incision and temperature of cooling water to avoid the“crack layer”. We choose the speed of incision to be 1 millimeter per minute and the thickness of wafer is about 2.5 millimeter after repeated experiments..In the course of the grind of the CZT wafer, the rate of grind is vitally important while the pressure is determinate. Low rate of grind leads to low efficiency, while high rate might make CZT wafer crack, even crash, resulting in the unsteadiness of the instrument which causes the roughness of the surface. Through repeated testing and studying, we draw a conclusion that the optimum rate of the grind of the CZT wafer is 40 revs per minute.After the mechanical polishing, the surface of the CZT wafers appears very luminant and smooth by the naked eye, but a lot of nicks and spots can be observed on the surface of the CZT wafers by the optical microscope. Br-methanol (BM) and Br-lactic acid-glycol(LB) solutions which could decrease the surface roughness effectively were employed to polish the CZT surface,and a possible polishing更多还原