以ZnO为换能材料的β辐射伏特效应核电池可行性探究

发布时间：2018-05-16 19:10

本文选题：氧化锌 + β辐射伏特效应　；参考：《吉林大学》2017年硕士论文

【摘要】：ZnO是材料学研究的热点之一,它是一种宽禁带半导体材料,具有高的击穿强度、饱和漂移速度以及极强的抗辐射性能,在高速器件和空间器件方面具有应用潜能。本文汇总了ZnO的n型及p型掺杂研究进展情况,使用ZnO作为β辐射伏特效应核电池换能材料,~(63)Ni及~(147)Pm作为β源,利用MCNP5程序进行模拟计算,获得了ZnO基β辐射伏特效应核电池的理论电学特性数据,计算结果可为进一步优化电学性能提供依据。本文主要研究以下内容:1.对单能电子在材料中的的输运情况进行研究,模拟单能准直电子、4π电子在换能材料ZnO、电极材料Al、Ag、Cu、Au中,定义能量减少为入射能量的1/10时的射程R1和能量减少为入射能量的1/100时的射程R2分别作为耗尽层宽度的参考值和防护材料厚度参考值,寻找两种射程与模拟材料特性参数的关系,并与较常用的电子射程经验公式进行比较,间接证明两种射程模拟的可靠性,为换能材料及防护材料的厚度选择提供依据。2.研究单能电子在换能材料和电极材料中的反散射问题,包括两部分:一是在换能材料中,电子束能量确定,反散射情况随入射角度的变化关系;二是在换能材料和电极材料中,给定入射角度(垂直于材料表面),反散射情况与入射电子能量的变化关系。由于反散射过程的实质是入射电子与靶物质原子核库仑场的相互作用,可得出反散射率与材料等效原子序数呈正相关。3.研究单能电子在换能材料和电极材料中的能量沉积情况,包括不同能量段的电子在换能材料ZnO中的能量沉积情况,以及20 ke V和60 ke V电子在不同材料中的能量沉积情况。由于放射源出射能谱可看做叠加的多种单能电子,此结果对于放射源的能量沉积区域的确定具有指导意义。4.模拟计算不同活度的~(63)Ni及~(147)Pm放射源自吸收情况,通过自吸收率与表面出射活度的比较选取合适活度的放射源。对于100%纯度的~(63)Ni放射源,选取总活度为0.02231 Ci;对于100%纯度的~(147)Pm源,选取总活度为3.34965 Ci。5.使用P区掺杂浓度为1.45×10~(18) cm~(-3),N区掺杂浓度为1.97×1020 cm~(-3)的ZnO同质PN结,内建电场为1.58 V,耗尽层宽度为32.6μm,短路电流为:~(63)Ni源为0.00391μA,~(147)Pm源为26.18μA;填充因子均为91.74%,最大输出功率分别为0.0567μW和37.95μW,转化效率分别为4.12%和4.59%。6.选取ND在2×10~(18)~1×10~(23) cm~(-3)之间,NA在1×10~(18)~1×1020 cm~(-3)的ZnO薄膜,初步讨论了掺杂浓度与内建电势和耗尽层宽度的关系。为更好地与~(63)Ni源能量沉积区(约6μm)匹配,可对掺杂浓度进一步优化:p区掺杂浓度应大于5×1019 cm~(-3),n区掺杂浓度不需过大。
[Abstract]:ZnO is one of the hot research fields in materials science. It is a wide band gap semiconductor material with high breakdown strength, high saturation drift velocity and strong radiation resistance. It has potential applications in high speed devices and space devices. In this paper, the research progress of n-type and p-type doping of ZnO is summarized. Using ZnO as the transfer materials of 尾 -radiative Voltage-effecting nuclear cell, and Pm as 尾 source, the simulation calculation is carried out by using MCNP5 program. The theoretical data of electrical properties of ZnO based 尾 -radiation effect nuclear cells are obtained. The calculated results can provide a basis for further optimization of electrical performance. This paper mainly studies the following contents: 1. The transport of single energy electrons in materials is studied. The range R 1 when the energy is reduced to 1 / 10 of the incident energy and the range R2 when the energy is reduced to 1 / 100 of the incident energy are used as the reference values of the depletion layer width and the thickness of the protective material, respectively. The relationship between the two kinds of range and the characteristic parameters of simulated materials is found, and compared with the empirical formula of electronic range, the reliability of the simulation of the two ranges is proved indirectly, which provides a basis for the thickness selection of the energy transfer material and the protective material. In this paper, the inverse scattering of single energy electrons in energy transfer materials and electrode materials is studied, which includes two parts: one is that the energy of the electron beam is determined in the transfer materials, the other is the relationship between the backscattering and the incident angle, and the second is in the energy transfer materials and the electrode materials. The relation between the incident angle (perpendicular to the surface of the material) and the incident electron energy is obtained. Since the essence of the backscattering process is the interaction between the incident electron and the Coulomb field of the target nucleus, it can be concluded that the backscattering rate is positively correlated with the equivalent atomic number of the material. The energy deposition of single energy electrons in energy transfer materials and electrode materials was studied, including the energy deposition of electrons of different energy segments in ZnO, and the energy deposition of 20ke V and 60ke V electrons in different materials. Since the emission spectra of radioactive sources can be regarded as superimposed single energy electrons, this result is of guiding significance for the determination of energy deposition regions of radioactive sources. The self-absorption of the radioactive sources with different activities, such as Ni and 147Pm, was simulated, and the suitable radioactive sources were selected by comparing the self-absorption rate with the surface exhalation activity. The total activity was 0.02231 Cii for the 100% pure Ni source and 3.34965 Ci.5for the 100% pure Pm source. ZnO homogenous PN junctions with P doping concentration of 1.45 脳 10 ~ (18) cm ~ (3) and N ~ (1. 97 脳 1020 cm ~ (-1) ~ (-1) were used. The internal electric field is 1.58 V, the width of depletion layer is 32.6 渭 m, the short-circuit current is 0.00391 渭 A ~ (63) Ni source is 0.00391 渭 A, the filling factor is 91.74 渭 A, the maximum output power is 0.0567 渭 W and 37.95 渭 W, and the conversion efficiency is 4.12% and 4.59 路6, respectively. The ZnO films with ND between 2 脳 10 ~ (18) ~ 1 脳 10 ~ (3) cm ~ (-3) and na ~ (1 脳 10 ~ (18) ~ (18) ~ (1 脳 1020) cm ~ (-3) were selected. The relationship between the doping concentration and the potential and the width of the depletion layer was preliminarily discussed. In order to better match with the energy deposition area (about 6 渭 m) of the Ni source, the doping concentration in the w ~ p region should be more than 5 脳 1019 cm ~ (-1) ~ (-3) ~ (-1), and the doping concentration should not be too large.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM918

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