Doped n-type a-Se alloys for use in x-ray image detectors: preparation, thermal and electrical properties

用于 X 射线图像探测器的掺杂 n 型 a-Se 合金：制备、热性能和电性能

• 批准号: 434690-2012
• 负责人: Kasap, Safa
• 金额: $ 4.37万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=552687
• 关键词: Doped; type; Se; alloys; use

The proposed NSERC-CRD grant is in collaboration with the Analogic Canada (Anrad) Corporation in Montreal, and has the overall goal of synthesizing and characterizing stabilized n-type a-Se alloys in which the stabilization is achieved by increasing the As content from 2% to 10%A. The n-type a-Se is used in one of the key-layers in the a-Se x-ray image detector next to the positively biased metal electrode to reduce the dark current. However, the doping of a-Se with n-type dopants tends to crystallize the structure over time, and it is more difficult to fabricate than the i-layer. The goal of this CRD is to synthesize a range of Se(1-x)As(x) alloys with As content varied from 0.3 to 10%, and the alloys doped with various IA and IIA elements, and characterize their structural, thermal and electrical properties. The CRD project involves the following research: (a) synthesis of the base Se(1-x)As(x) alloys; (b) n-type doping of these Se(1-x)Se(x) alloys; (c) structural and thermal characterization of the new n-type alloys through differential scanning calorimetry (DSC) and temperature-modulated DSC to obtain the glass transition, crystallization and melting temperature, the heat capacity, relaxation and crystallization enthalpies, crystallization kinetics; (d) electrical properties through charge transport measurements (such as transient photoconductivity type time-of-flight measurements), dark current measurements, and excess noise experiments. The experimental work will be supplemented by the formulation of new useful models for the dark current so that it can be predicted as a function of time and applied field from the intrinsic material properties for x-ray detectors that will have the new n-type a-Se layer. The proposed CRD grant builds on the expertise gained in the previous CRD and therefore starts from an already established know-how and builds on strength. The results are expected to lead to enhancements in detector performance in terms of having the n-layer in the detector thinner and higher production yield. The research directly impacts a-Se x-ray detectors currently used in mammography; and also therefore impacts the healthcare of women (breast cancer screening).

拟议的NSERC-CRD拨款是与蒙特利尔的Analogic Canada (Anrad) Corporation合作的，其总体目标是合成和表征稳定的n型a-Se合金，其中通过将As含量从2%增加到10%来实现稳定。在a-Se x射线图像探测器的一个关键层中，在正偏置金属电极旁边使用n型a-Se，以减少暗电流。然而，随着时间的推移，用n型掺杂剂掺杂a-Se往往会使结构结晶，并且比i-层更难制造。本CRD的目标是合成一系列As含量在0.3 ~ 10%之间的Se(1-x)As(x)合金，以及掺杂各种IA和IIA元素的合金，并表征其结构、热学和电学性能。CRD项目包括以下研究：(a)合成Se(1-x)As(x)合金；(b)这些Se(1-x)Se(x)合金的n型掺杂；(c)通过差示扫描量热法（DSC）和调温DSC对新型n型合金进行了结构和热表征，获得了玻璃化转变、结晶和熔化温度、热容量、弛豫和结晶焓、结晶动力学；(d)通过电荷输运测量（如瞬态光电导率类型的飞行时间测量）、暗电流测量和过量噪声实验来测量电性能。实验工作将由新的有用的暗电流模型的制定来补充，这样就可以从具有新n型a- se层的x射线探测器的固有材料特性中预测它作为时间和应用场的函数。拟议的CRD资助以以前的CRD所获得的专业知识为基础，因此从已经建立的专业知识和实力开始。研究结果预计将导致探测器性能的增强，因为探测器中的n层更薄，产量更高。该研究直接影响了目前用于乳房x光检查的a-Se x射线探测器；因此也影响妇女的保健（乳腺癌筛查）。