Study On Performance Of Heterojunction Betavoltaic Nuclear Battery

A nuclear battery,also known as a radioisotope battery,is a device that converts the decay energy of radioactive isotopes into electricity.This paper mainly focuses on betavoltaic nuclear cells.In order to improve the output performance of betavoltaic nuclear battery and expand its application range.The short-circuit current density,open circuit voltage,filling factor,maximum output power density and conversion efficiency of nuclear cells formed by GaP-Si heterojunction,alloy-diamond heterojunction and integrated ⁶³NiO-Si heterojunction were theoretically calculated.The influence of the doping concentration,the thickness of the energy converter,the diffusion length of the minority carrier and the diffusion coefficient on the electrical output performance is discussed.The results provide a theoretical basis for the fabrication of nuclear batteries with corresponding structures.1.For GaP-Si heterojunction betavoltaic nuclear cell,MCNP is used to simulate the energy deposition of ⁶³Ni in GaP-Si,and then the output performance of nuclear cell under different thickness GaP and different doping concentration is calculated by formula.when the GaP thickness is 0.4μm and the silicon doping concentration is9.5×10¹⁷/cm~3,the maximum output power density,conversion efficiency,open-circuit voltage and short-circuit current density of GaP-Si heterojunction betavoltaic cell are0.189μW/cm~2,1.83%,0.81 V and 0.27μA/cm~2.2.For alloy-diamond heterojunction betavoltaic nuclear battery,MCNP simulates the energy deposition of radioactive source in energy exchanging material.By using theory formulas,the electrical output parameters of 2198 Al-Li alloy-diamond heterojunction battery and Al-diamond heterojunction battery are calculated and compared.The results show that the short-circuit current density,open-circuit voltage and maximum output power of 2198 Al-Li alloy schottky cell are increased by about3.63%,24.24%and 30.19%.3.For the integrated ⁶³NiO-Si heterojunction betavoltaic nuclear battery,MCNP is used to simulate the energy deposition of the energy exchanging material itself,and the structure of the ⁶³NiO-Si heterojunction is optimized by formula calculation.When the thickness of ⁶³NiO is 4μm and the silicon doping concentration is1×10¹⁵/cm~3,The short-circuit current density,open-circuit voltage,filling factor and maximum output power density of nuclear cell are 1.22μA/cm~2,3.17 V,0.95,3.67μW/cm~2,respectively.In addition,the output performance of ⁶³Ni/NiO-Si heterojunction betavoltaic nuclear cells is calculated.While the activity and thickness of NiO in the two structures are the same,the output performance of the ⁶³NiO-Si nuclear battery is greatly improved.n general,this thesis mainly starts from optimizing the energy conversion structure of the nuclear battery to improve the output performance of the nuclear battery.Attempts to calculate the output performance of GaP-Si heteronucleation cells by using the formula,and study the influence of structural parameters and doping concentration on the electrical output parameters.Unique advantages;in addition,in order to improve the output performance of Schottky type nuclear batteries,the Schottky metal was changed to an alloy to form a new Schottky structure,and the idea of using alloys in nuclear batteries was introduced into the research,theoretical calculation results The application of the reflected alloy has indeed improved the output performance of the nuclear battery;finally,in order to solve the self-absorption effect of the radioactive source,a 63NiO-Si heterogeneous nodule battery integrated with energy-carrying and energy-transduction is proposed,which makes full use of the energy of the radioactive source and greatly improves the performance of the nuclear battery.