Wide bandgap semiconductor conversion devices for radioisotope microbatteries
Wide bandgap semiconductor conversion devices for radioisotope microbatteries
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DOI：
10.1016/j.mssp.2022.106533
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发表时间：
2022-01-29
影响因子：
4.1
通讯作者：
Barnett，A. M.
中科院分区：
文献类型：
--
作者：
Lioliou，G.;Krysa，A. B.;Barnett，A. M.
为了了解不同半导体材料、器件结构和x射线入射功率之间的比较效应，并探索它们在未来放射性同位素微电池中的应用，研究了5个p+-i-n+平台光电二极管（每个面积为0.126 mm2）作为x射线电压的转换器件。研究了三种半导体材料（AlInP， InGaP和GaAs）和一种材料AlInP （2 μm， 6 μm和10 μm）的三种i层厚度在不同控制x射线入射功率下的发光特性。由于其最厚的有源层和最高的线性吸收系数（Mo Kα为17.48 keV， Mo Kβ为19.6 keV）， GaAs器件获得了最大的短路电流。10 μm AlInP器件由于具有最宽的带隙（如InGaP和GaAs）和最大的短路电流（如2 μm和6 μm AlInP器件）而实现了最高的开路电压。与其他器件相比，InGaP器件由于其最高的填充因子（即相对较低的串联电阻和较高的分流电阻）而记录了最大的x射线输出功率，尽管GaAs器件具有最高的理论输出x射线功率。在考虑入射x射线光谱的情况下，提出了一种选择最合适的半导体材料和用于放射性同位素微电池转换装置的器件结构（以显示最高的功率输出）的方法，同时强调了非理想器件效应（降低电荷收集效率，增加串联电阻和降低分流电阻）的重要性。
Five mesa p+-i-n+photodiodes (each of 0.126 mm2area) were investigated as conversion devices for X-ray-voltaics, in order to understand the comparative effects between different semiconductor materials, device structures, and X-ray incident power, and to explore them for use in future radioisotope microbatteries. Three semiconductor materials (AlInP, InGaP, and GaAs) and three i layer thicknesses of one material, AlInP (2 μm, 6 μm, and 10 μm), were investigated under the illumination of various controlled X-ray incident powers. The highest short circuit current was achieved with the GaAs device due to its thickest active layer and highest linear absorption coefficients at the most numerous incident X-ray photon energies (Mo Kα at 17.48 keV; Mo Kβ at 19.6 keV). The highest open circuit voltage was achieved with the 10 μm AlInP device due to its widest bandgap (cf. InGaP and GaAs) and its highest short circuit current (cf. the 2 μm and the 6 μm AlInP devices). The greatest output X-ray power was recorded with the InGaP device due to its highest fill factor (i.e. relatively low series and high shunt resistance) compared to the rest of the devices, although the GaAs device had the highest theoretical output X-ray power. A method for selecting the most suitable semiconductor material and device structure of conversion devices for radioisotope microbatteries (for exhibiting the highest power output) is presented considering the incident X-ray spectrum, while highlighting the importance of non-ideal device effects (reduced charge collection efficiency, increased series resistance, and reduced shunt resistance).