High spatial resolution direct conversion amorphous selenium X-ray detectors with monolithically integrated CMOS readout
High spatial resolution direct conversion amorphous selenium X-ray detectors with monolithically integrated CMOS readout
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DOI：
10.1088/1748-0221/18/04/p04021
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发表时间：
2023-04-01
影响因子：
1.3
通讯作者：
Goldan，A.
中科院分区：
文献类型：
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作者：
Han，Z.;Mukherjee，A.;Goldan，A.
用于高能同步辐射光源的微米级空间分辨率直接转换X射线探测器领域的最新进展服务于从无损和非侵入性显微技术到医疗诊断测量设备的各种应用。非晶态硒(a-Se)作为一种宽禁带热蒸发光电导体，对暗载流子具有极低的发热率，在X射线医学成像中得到了广泛的应用。作为一种非晶态材料，它可以在室温下以比晶体半导体低得多的成本大面积沉积。为了满足同步辐射光源对高能、高空间分辨率X射线探测器的需求，我们在混合模式像素阵列探测器(MM-PAD)专用集成电路(ASIC)上热蒸发了Se。ASIC格式由128×128正方形像素组成，每侧150μm。在专用集成电路上直接沉积了一层200μ的a-Se层，然后在其上沉积了金属顶电极。用45kVAg和23kVCuX射线管源对完成的探测器组件进行了测试。报道了探测器的制作、性能、调制传递函数(MTF)测量和模拟。
Recent progress in the field of micron-scale spatial resolution direct conversion X-ray detectors for high-energy synchrotron light sources serve applications ranging from nondestructive and noninvasive microscopy techniques which provide insight into the structure and morphology of crystals, to medical diagnostic measurement devices. Amorphous selenium (a-Se) as a wide-bandgap thermally evaporated photoconductor exhibits ultra-low thermal generation rates for dark carriers and has been extensively used in X-ray medical imaging. Being an amorphous material, it can further be deposited over large areas at room temperatures and at substantially lower costs as compared to crystalline semiconductors. To address the demands for a high-energy and high spatial resolution X-ray detector for synchrotron light source applications, we have thermally evaporated a-Se on a Mixed-Mode Pixel Array Detector (MM-PAD) Application Specific Integrated Circuit (ASIC). The ASIC format consists of 128× 128 square pixels each 150 μm on a side. A 200 μm a-Se layer was directly deposited on the ASIC followed by a metal top electrode. The completed detector assembly was tested with 45 kV Ag and 23 kV Cu X-ray tube sources. The detector fabrication, performances, Modulation Transfer Function (MTF) measurements, and simulations are reported.