A trajectory model of incident electrons in semiconductor materials is built using Monte Carlo method,and based on this model,simulation can be carried out to achieve penetration depth and energy distribution of incident electrons in semiconductors.GaN PN junction betavoltaic microbatteries using radioisotopes Ni-63 as sources are studied to obtain the penetration path and energy distribution of incident electrons into GaN.The area where the beta energy is concentrated in GaN can be shown by analyzing simulation result,and the collection efficiency of beta energy can be highly increased if the PN junction depth of the GaN microbattery is set near the depth where the beta energy is concentrated.Experimentally,GaN betavohaic microbatteries using Ni-63 as source,with depth of junction is 1000,450 nm separately,are fabricated and tested,and the result shows that the electrical output performance of the microbattery is greatly improved when the microbattery has its junction depth optimized by Monte Carlo method.The energy conversion efficiency of the developed GaN microbattery is tested as 1.47 ％ and output power is in the scale of microwatt.The result can provide effective reference for design and fabrication of GaN beta-voltaic microbattery.%应用Monte Carlo方法,建立了电子入射到半导体材料中的路径模型.基于此模型进行仿真,可以得到电子在半导体材料中的穿透深度和能量分布.对以同位素Ni-63为放射源的GaN基PN结微型核电池进行Monte Carlo分析,得出入射电子在GaN中的穿透路径和能量分布,以确定入射电子在GaN中能量最集中的位置,将GaN基PN结的结深设置在该位置可以大幅提高收集效率,进而提高输出功率与能量转换效率.实验中,分别制备了结深为1000,450 nm,放射源为Ni-63的GaN基微型核电池,测试结果验证了经优化结深为450 nm的微型核电池其电学输出性能有明显提高,能量转换效率达到了1.47％,输出功率达到了微瓦级.该结果可以为GaN基微型核电池的设计与制造提供有效的参考依据.
展开▼
