用于X射线超导转变边缘传感器的铋吸收体的电镀沉积

Electroplating Deposition of Bismuth Absorbers for X-ray Superconducting Transition Edge Sensors.

作者信息

Chen Jian, Li Jinjin, Xu Xiaolong, Wang Zhenyu, Guo Siming, Jiang Zheng, Gao Huifang, Zhong Qing, Zhong Yuan, Zeng Jiusun, Wang Xueshen

机构信息

National Institute of Metrology (NIM), Beijing 100029, China.

College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China.

出版信息

Materials (Basel). 2021 Nov 25;14(23):7169. doi: 10.3390/ma14237169.

DOI:10.3390/ma14237169

PMID:34885323

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8658586/

Abstract

An absorber with a high absorbing efficiency is crucial for X-ray transition edge sensors (TESs) to realize high quantum efficiency and the best energy resolution. Semimetal Bismuth (Bi) has shown greater superiority than gold (Au) as the absorber due to the low specific heat capacity, which is two orders of magnitude smaller. The electroplating process of Bi films is investigated. The Bi grains show a polycrystalline rhombohedral structure, and the X-ray diffraction (XRD) patterns show a typical crystal orientation of (012). The average grain size becomes larger as the electroplating current density and the thickness increase, and the orientation of Bi grains changes as the temperature increases. The residual resistance ratio (RRR) (/) is 1.37 for the Bi film (862 nm) deposited with 9 mA/cm at 40 °C for 2 min. The absorptivity of the 5 μm thick Bi films is 40.3% and 30.7% for 10 keV and 15.6 keV X-ray radiation respectively, which shows that Bi films are a good candidate as the absorber of X-ray TESs.

摘要

对于X射线转变边缘传感器（TES）而言，具有高吸收效率的吸收体对于实现高量子效率和最佳能量分辨率至关重要。半金属铋（Bi）作为吸收体已显示出比金（Au）更大的优势，这归因于其低比热容，比金小两个数量级。对铋膜的电镀工艺进行了研究。铋晶粒呈现多晶菱面体结构，X射线衍射（XRD）图谱显示出典型的（012）晶体取向。随着电镀电流密度和厚度增加，平均晶粒尺寸变大，并且随着温度升高，铋晶粒的取向发生变化。在40°C下以9 mA/cm²的电流密度电镀2分钟沉积的铋膜（862 nm）的剩余电阻比（RRR）为1.37。对于10 keV和15.6 keV的X射线辐射，5μm厚铋膜的吸收率分别为40.3%和30.7%，这表明铋膜是作为X射线TES吸收体的良好候选材料。