GaAs基β辐射伏特效应微电池的参量优化设计研究

考虑放射性同位素源自吸收效应，提出基于半导体材料GaAs和同位素源⁶³Ni的微电池最优化设计方案，并通过蒙特卡罗程序MCNP模拟计算β粒子在半导体材料中的输运过程，对同位素源与半导体材料的厚度，换能单元PN结结深、耗尽区宽度、掺杂浓度、少子扩散长度，及电子空穴对的产生及收集情况等进行了研究和分析，给出了不同结深下，各物理参量的最佳设计值。在源活度为3.7×10⁷ Bq，PN结表面积为0.01 cm²时，提出的辐射伏特效应微电池最优化设计方案可实现：短路电流密度为379.68 nA/cm²，开路电压为1.375 V，填充因子为84.39%, 最大输出功率为440.4 nW/cm²，能量转化率为4.34%。

Parameters Optimization of GaAs Betavoltaic Microbattery

A design scheme of microbattery with semiconductor material GaAs and isotope ⁶³Ni was presented. In consideration of the isotope’s self-absorption effect, the current paper studied and analyzed the thickness of semiconductor and isotope source, PN junction depth, depletion region thickness, doping concentration, minority carrier diffusion length and the generation and collection of electron hole pairs with simulation of transport process of beta particles in semiconductor material using Monte-Carlo simulation program MCNP. The optimization output performances and corresponding parameter values of the microbattery under different junction depths were obtained. For the proposed design scheme, when the activity of radioisotope is 3.7×10⁷ Bq, and the surface area of PN junction is 0.01 cm², the optimization result is that short circuit current density, open circuit voltage, fill factor, maximum output power and efficiency of a single device are 379.68 nA/cm², 1.375 V, 84.39%, 440.4 nW/cm² and 4.34%, respectively.