在X射线诊断成像方面,非晶硒(a-Se)是最有前途的探测材料之一.通过实验研究了a-Se合金膜的制备方法,用飞行时间方法测量了载流子的漂移迁移率和寿命,讨论了对a-Se合金膜性能有重要影响的因素.通过对400 μm厚a-Se合金膜X 射线光电流的测量,确定了a-Se合金膜对X射线的光电响应特性.实验表明,a-Se合金膜具有线性的光电转换特性;灵敏度与场强有关.在10 V/μm场强下,对于医疗诊断常用的轫致辐射X射线谱,用X射线在a-Se合金膜中产生一电子-空穴对约需45 eV的能量.

Amorphous selenium alloy (a Se alloy) is currently of great interest as X ray imaging receptor due to its high resolution. The a Se alloy films are deposited by vacuum evaporation, the transport properties of hole and electron are measured by time of flight technique. Some factors, which affect the properties of a Se alloy film, are discussed. X ray photocurrent is measured by using 400μm thick film. The results show that linear photoelectric conversion existed in a Se alloy film, and its sensitivity to X ray irradiation depends on electric field. The calculation indicates that about 45 eV is needed for X ray to release an electric hole pair in a Se alloy film at 10 V/μm electric field.