High-performance x-ray source based on graphene oxide-coated Cu(2)S nanowires grown on copper film.
High-performance x-ray source based on graphene oxide-coated Cu(2)S nanowires grown on copper film.
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基于铜膜上生长的氧化石墨烯涂层 Cu(2)S 纳米线的高性能 X 射线源。
DOI：
10.1088/1361-6528/abb0b6
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发表时间：
2020
期刊：
影响因子：
3.5
通讯作者：
Chen Ming
中科院分区：
文献类型：
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作者：
Zhang Daoshu;Zhang Siyuan;He Ke;Wang Libin;Sui Fan;Hong Xuda;Li Weiwei;Li Nianci;Jia Meiling;Li Weimin;Wang Zhixun;Wang Zongpeng;Du Bi;Wei Lei;Feng Ye;Zhong Guohua;Li Wenjie;Chen Jun;Yang Chunlei;Chen Ming
全静态X射线计算机层析成像(CT)技术具有更高的成像精度和分辨率，在诊断医学成像、工业检测和安检等领域得到了广泛的应用。在这项技术中，X射线源部分主要由热离子阴极和电子束扫描系统组成。但它们都存在扫描角度小、响应时间长、体积大等缺点。分布式、可编程冷阴极(即碳纳米管、氧化锌纳米线)场发射X射线源有望解决这些问题。然而，这种冷场发射器在X射线源中的应用面临着几个长期的挑战，例如寿命短和严格的制造工艺，这从根本上阻碍了它们的广泛使用。在这里，我们提出并演示了一种基于氧化石墨烯(GO)涂覆硫化亚铜纳米线(Cu2 S NW/GO)阴极的冷场发射X射线源。所研制的Cu2 S NW/GO X射线源发射稳定(在2600V直流电压下发射18h)，阈值低(4.5mV m−1，获得1μA cm−2的电流密度)，这得益于Cu2 S NW在铜上的原位外延生长，GO内纳米级的尖锐突起，以及Cu2 S NW和GO层之间的电荷转移。我们的研究为获得高性能冷场发射体提供了一种简单而可靠的方法，为下一代X射线源和CT带来了巨大的潜力。
Full static x-ray computed tomography (CT) technology has enabled higher precision and resolution imaging and has been applied in many applications such as diagnostic medical imaging, industrial inspection and security screening. In this technique, the x-ray source section is mainly composed of a thermionic cathode and electron beam scanning system. However, they have several shortcomings such as limited scanning angle, long response time and large volume. Distributed and programmable cold cathode (ie carbon nanotubes, ZnO nanowires (NWs)) field-emission x-ray sources are expected to solve these problems. However, there have been several long-standing challenges to the application of such cold field emitters for x-ray sources, such as the short lifetime and rigorous fabrication process, which have fundamentally prevented their widespread use. Here, we propose and demonstrate a cold field-emission x-ray source based on a graphene oxide (GO)-coated cuprous sulfide nanowire (Cu 2 S NW/GO) cathode. The proposed Cu 2 S NW/GO x-ray source provides stable emission (> 18 h at a direct voltage of 2600 V) and has a low threshold (4.5 MV m− 1 for obtaining a current density of 1 μA cm− 2), benefiting from the demonstrated key features such as in situ epitaxy growth of Cu 2 S NWs on Cu, nanometer-scale sharp protrusions within GO and charge transfer between the Cu 2 S NWs and GO layer. Our research provides a simple and robust method to obtain a high-performance cold field emitter, leading to great potential for the next generation of x-ray source and CT.