4H-SiC肖特基微型同位素电池(英文)

半导体同位素电池由于其寿命长、集成性优良、环境适应性强等特点成为解决MEMS能源问题的理想手段。利用4H-SiC材料的宽禁带特性,制造了4H-SiC肖特基同位素电池。对电池的耗尽层厚度以及掺杂浓度进行了优化设计,对肖特基金属进行了选择。使用4mCi/cm2的63Ni作为同位素电池的放射源对制造的同位素电池进行了测试。测试结果表明,该同位素电池可以获得31.3nW/cm2的功率密度、0.5V的开路电压、3.13×10-8A/cm2的短路电流密度和1.3%的转换效率。将电池的输出特性和硅基的平板型、3D结构电池输出特性进行了比较,证明4H-SiC肖特基同位素电池能够获得较高的功率密度。电池的性能可通过提升势垒高度、提高工艺质量、更换同位素等方式得到提高。     

GaAs基辐射福特效应电池电极图案设计

研究了串并联电阻对太阳能电池和β伏特效应电池的影响, 并在此基础上提出了GaAs基β伏特效应电池的电极图案设计原则。在该原则的指导下设计了一批GaAs基PIN结的电极图案,测试了这些PIN结在⁶³Ni源辐照下的输出特性。与传统的梳状电极相比,本文电极设计可以降低对⁶³Ni辐射β粒子的反散射和阻挡作用,有效的增加了电池的输出电流,而这种电极设计不会对电池的开路电压,填充因子和理想因子带来不利的影响。     

Design and optimization of radioisotope sources for betavoltaic batteries

A Monte Carlo source model using PENELOPE was developed to investigate different tritiated metals in order to design a better radioisotope source for betavoltaic batteries. The source model takes into account the self‐absorption of beta particles in the source which is a major factor for an efficient source design. The average beta energy, beta flux, source power output, and source efficiency were estimated for various source thicknesses. The simulated results for titanium tritide with 0° and 90° angular distributions of beta particles were validated with experimental results. The importance of the backscattering effect due to isotropic particle emission was analyzed. The results showed that the normalized average beta energy increases with the source thickness, and it reaches peak energy depending on the density and the specific activity of the source. The beta flux and power output also increase with increasing source thickness. However, the incremental increase in beta flux and power output becomes minimal for higher thicknesses, as the source efficiency decreases significantly at higher thicknesses due to the self‐absorption effect. Thus, a saturation threshold is reached. A low‐density source material such as beryllium tritide provided a higher power output with higher efficiency. A maximum power output of approximately 4 mW/cm³ was obtained for beryllium tritide with SiC. A form factor approach was used to estimate the optimum source thickness. The optimum source thickness was found near the thickness where the peak beta particle average energy occurs.     

半导体器件在辐射作用下的电学输出性能研究

半导体结型器件是决定辐射伏特效应同位素电池能量转换效率的核心部件。采用加速器产生的不同能量电子束和63Ni源的β射线对硅基PIN结型器件进行辐照,在线测量了其电学输出性能。当电子束能量为18 keV,可得到大于4%的能量转换效率;电子束能量为6 keV,能量转换效率在0.16%～0.33%之间; 活度2.96×108 Bq的63Ni源片辐照的能量转换效率为0.1%左右。     

GaN PIN betavoltaic nuclear batteries

GaN PIN betavoltaic nuclear batteries are demonstrated in this work.GaN epitaxial layers were grown on 2-inch sapphire sub-strates by MOCVD,and then the GaN PIN nuclear batteries were fabricated.Current-voltage(I-V)characteristic shows that the small leakage currents are 0.12 nA at 0 V and 1.76 nA at 10 V,respectively.With 147Pm the irradiation source,the maximum open circuit voltage and maximum short circuit current are 1.07 V and 0.554 nA,respectively.The fill factor(FF)of24.7%for the battery was been obtained.The limited performance of the devices is mainly due to the low energy deposition in the microbatteries.Therefore,the GaN nuclear microbatteries are expected to be optimized by growing high quality GaN films,thin dead layer and so on.     

一种新型基于MEMS的同位素微电池的研究

介绍了同位素微电池的工作原理及结构组成.阐明了其从工作原理上区别于原有的核电池,采用和太阳能电池光生伏特相似的辐生伏特效应.对同位素微电池的工艺作了详尽的介绍.提出了使用垂直侧壁方孔阵列的能量转换结构,相比传统的同尺寸开口且等深的倒三角直槽型或倒金字塔型的能量转换结构表面积增大了120%以上;引入了电镀区这一新结构,增强了同位素微电池的工作稳定性.     

氚钛片辐照硅基半导体器件电学输出性能

制备了多个不同厚度金属钛膜吸附不同量^3H的氚钛片,利用这些源片辐照硅基半导体器件,测试并分析了它们的电学输出性能。结果表明,这些氚钛片辐照硅基半导体器件可以输出电流,但由于金属钛对氚源β射线的阻挡,器件输出电流和最大输出功率与钛膜中贮氚量不呈正比增长关系,小的钛膜厚度有利于提高β射线能量利用率。     

Electrode pattern design for GaAs betavoltaic batteries

The sensitivities of betavoltaic batteries and photovoltaic batteries to series and parallel resistance are studied.Based on the study,an electrode pattern design principle of GaAs betavoltaic batteries is proposed.GaAs PIN junctions with and without the proposed electrode pattern are fabricated and measured under the illumination of ⁶³Ni.Results show that the proposed electrode can reduce the backscattering and shadowing for the beta particles from ⁶³Ni to increase the GaAs betavoltaic battery short circuit currents effectively but has little impact on the fill factors and ideal factors.     

β辐射伏特效应电池内建电场厚度设计

计算了放射源在半导体中沿厚度方向的能量沉积,并以此计算β辐射伏特效应电池的理想短路电流。通过对比实测短路电流和理想短路电流可以得到β辐射伏特效应电池PN结内建电场的扩散长度。在上述基础上,本文给出了β辐射伏特效应电池内建电场厚度设计原则： 放射源在半导体中能量沉积厚度和PN结内建电场中载流子的扩散长度两者中较小的应作为β伏特效应电池内建电场厚度设计值,如果沉积厚度远远大于载流子扩散长度,则说明多结结构较适合该类β伏特效应电池果,多结的结数应约为沉积厚度与载流子扩散长度的比。     

辐伏同位素电池开路电压与温度关系分析

单晶硅PN结换能单元辐射伏特效应同位素电池(简称辐伏电池)开路电压温度效应很明显,通过分析与辐伏电池开路电压相关的因素,认为基本参数中基层掺杂浓度和短路电流对开路电压与温度的关系有显著影响,而顶层掺杂浓度影响非常小。大的基层掺杂浓度和短路电流对于较高温度环境中辐伏电池输出开路电压是有利的。