Minns Allan, Mahajan Tushar, Tokranov Vadim, Yakimov Michael, Hedges Michael, Murat Pavel, Oktyabrsky Serge
College of Nanotechnology, Science and Engineering, University at Albany, State University of New York, Albany, NY, USA.
Fermi National Accelerator Laboratory, Batavia, IL, USA.
Sci Rep. 2024 Oct 2;14(1):22870. doi: 10.1038/s41598-024-74160-7.
Epitaxial quantum dot (QD) scintillator crystals with picosecond-scale timing and high light yield have been created for medical imaging, high energy physics and national security applications. Monolithic photodetector (PD) integration enables the sensing of photons generated within the waveguiding crystal and allows a wide range of scintillator-photodetector coupling geometries. Until recently, these doubly novel devices have suffered from complex, high variance responses to monoenergetic sources which significantly reduces their precision and accuracy. The principles governing the overall device response have now been discerned and embodied by an expression derived within a geometrical optics framework which considers optical properties, surface roughness and photodetector coupling geometry. Response variation due to these factors was sufficiently reduced to obtain material-related energy resolution values of 2.4% with alpha particles. These findings place energy resolution alongside luminescence timescale, photon yield, and radiation hardness as outstanding properties of these engineered materials.
已制造出具有皮秒级定时和高光输出的外延量子点（QD）闪烁体晶体，用于医学成像、高能物理和国家安全应用。单片光电探测器（PD）集成能够感应波导晶体内产生的光子，并允许采用多种闪烁体 - 光电探测器耦合几何结构。直到最近，这些具有双重新颖性的器件对单能源的响应复杂且变化很大，这显著降低了它们的精度和准确性。现在，通过在几何光学框架内推导得出的一个表达式，已经识别并体现了支配整个器件响应的原理，该表达式考虑了光学特性、表面粗糙度和光电探测器耦合几何结构。由于这些因素导致的响应变化已充分降低，使用α粒子时可获得与材料相关的2.4%的能量分辨率值。这些发现使能量分辨率与发光时间尺度、光子产量和辐射硬度一起，成为这些工程材料的突出特性。
