较为全面地考查了非晶硒对X射线的灵敏度。引入一个灵敏度模型 ,在灵敏度与载流子迁移特性、光子能量、非晶硒厚度和场强之间建立了明确的关系。计算结果表明,载流子迁移长度至少应是非晶硒厚度的2倍以上,才能使 X射线激发的电子、空穴有较大的概率到达收集电极(或非晶硒自由表面)(即信号收集效率);用加大非晶硒厚度的方法增加灵敏度时必须考虑信号收集效率降低的负面影响;场强对灵敏度有重要影响,提高场强可使非晶硒灵敏度显著增加。改变场强是调节灵敏度的有效方法。

The sensitivity of amorphous selenium (a-Se) for X-ray imaging is discussed in detail, and a sensitivity model, related to charge carrier schubwegs, X-ray photon energy, a-Se layer thickness and electric field, is introduced. Calculation results show that the carrier schubwegs can significantly reduce the sensitivity of a-Se if they are shorter than twifold layer thickness, which means that attention must be paid to carrier schubwegs while designing layer thickness or preparing a-Se material. The sensitivity of a-Se strongly depends on the electric field, so increasing electric field is an effective way to increase the sensitivity.