Performance Comparison Of GaAs Betavoltaic Battery Based On ⁶³Ni?¹⁴⁷Pm And ³H

The nuclear batteries(or radioisotope batteries)are the devices,which convert the decay energy of radioisotopes into the electrical energy.With the development of GaAs semiconductor material,the GaAs-based batteries showed a good output performance.Based on the Monte Carlo Method and the code MCNP,this paper presents a theoretical calculation model of GaAs p-n junction-based betavoltaic batteries with the 63Ni,147Pm and 3H sources.These results are essential for the optimal designs and fabrications of relevant batteries.The main work of this paper includes three respects as follows:1.The self-absorption effect of the beta sources 63Ni,147Pm and 3H.The Monte Carlo Method is used to simulate the particle emission on the surface and the energy deposition distribution inside the matter of different kinds of radiation sources with different thicknesses.In order to obtain the maximum apparent performance of a selected source,for 63Ni,the thickness of source should not larger than 2 ?m;for 147Pm,the thickness of source should not larger than 28 ?m;for 3H,the thickness of source should not larger than 1 ?m.2.The deposited energy distribution of the 63Ni,147Pm and 3H(the ratio of 3H to Ti is 1.8:1)sources in the energy converter material GaAs are obtained.It is shown that when the radiation transport depth of the 63Ni source in the GaAs material reaches 4-5?m,the energy deposition percentage reaches 90%;when the radiation transport depth of the 147Pm source in the GaAs material reaches 43-45 ?m,the energy deposition percentage reaches 90%;when the radiation transport depth of the 3H(the ratio of 3H to Ti is 1.8:1)source in the GaAs material reaches 0.7-1.0 ?m,the energy deposition percentage reaches 90%.It is observed that the main transport scale length in the material is different for different radiation sources.3.Based on the theoretical formula of a betavoltaic battery,the theoretical output parameters of GaAs-63Ni,GaAs-147Pm and GaAs-3H nuclear batteries are obtained and compared.The output performance of these three kinds of nuclear power batteries have their own advantages and disadvantages.Therefore,different types of betavoltaic batteries can be fabricated according to actual needs in the preparation process.