Bismuth chalcohalide-based nanocomposite for application in ionising radiation detectors
Bismuth chalcohalide-based nanocomposite for application in ionising radiation detectors
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DOI：
10.1088/1361-6528/ab7675
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发表时间：
2020-05-29
期刊：
影响因子：
3.5
通讯作者：
Aguiar, Ivana
中科院分区：
文献类型：
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作者：
Frutos, Maia Mombru;Barthaburu, Maria Eugenia Perez;Aguiar, Ivana
硫碘化铋（BiSI）属于硫族卤化物家族，其呈现出若干吸引人的电光性质。特别地，BiSI是一种半导体，由于1.6 eV的带隙、6.4 g cm（-3）的密度和5.6 cm（2）g（-1）的60 keV辐射吸收系数，其可以用于X和伽马射线检测。这项工作提出了在溶剂热条件下轻松合成由BiSI纳米棒和无定形碳结构组成的纳米复合材料。此外，它还研究了其在室温下的电离辐射探测特性，当时原型探测器是由小球制成的。还研究了颗粒的构造条件，改变施加的压力和对纳米复合材料的热处理。暗电流密度和响应不同的曝光率的Am-241源的原型探测器建成测量。有人发现，热处理的颗粒显着提高探测器的性能。暗电流密度比未经热处理的粒料低一个数量级，并且其对Am-241源的响应是线性的，对于20 V，信噪比为7。最后，经热处理的检测器的电阻率为10（11）Ω cm的数量级，与针对该应用研究的其它材料相当。
Bismuth sulpho iodide (BiSI) belongs to the family of chalcohalides, which present several attractive electro-optic properties. In particular, BiSI is a semiconductor which could be used in X and gamma ray detection due to a band gap of 1.6 eV, density of 6.4 g cm(-3), and absorption coefficient for 60 keV radiation of 5.6 cm(2) g(-1). This work presents a facile synthesis under solvothermal conditions of a nanocomposite consisting of BiSI nanorods and amorphous carbon structures. Furthermore, it studies its ionising radiation detection properties at room temperature, when prototype detectors were built from pellets. The construction conditions of pellets were also studied, varying the applied pressure and heat treatment to the nanocomposite. Dark current density and response to different exposure rates of a Am-241 source were measured for the prototype detectors built. It was found that heat treatment of pellets considerably improves detectors performance. Dark current density was one order of magnitude lower than for the pellets without heat treatment, and its response to the Am-241 source, linear, with a signal to noise ratio of 7 for 20 V. Finally, the resistivity for the heat treated detector was in the order of 10(11) omega cm, comparable to other materials studied for this application.