Exploratory study of betavoltaic nuclear battery using AlN P-N junction

In most of the betavoltaic nuclear batteries, wide band semiconductors such as GaN and SiC have been used as an energy converter. But, the growth of these semiconductors are relatively expensive. In the present work, a new study was conducted on betavoltaic nuclear batteries. In this study, AlN betavoltaic nuclear battery driven by an 90Sr + 90Y radioisotope source was investigated. AlN is wide band semiconductor and economically viable. Then, by Monte Carlo simulation the effects of factors such as type of electrode, dimensions, thickness, and geometric model of P-N junction on the battery efficiency were investigated. Finally, it was found that the cubical model has the highest amount of short circuit current, open circuit voltage, and battery efficiency. The value of short circuit current, open circuit voltage, and battery efficiency in this model are 406.05 nA, 5.43 V, and 5.16 %, respectively. In order to compare the efficiency of AlN betavoltaic nuclear battery with the efficiency of GaN and SiC betavoltaic nuclear batteries, first the optimal dimensions were investigated for each of GaN and SiC betavoltaic nuclear batteries and then based on the optimal dimensions obtained for GaN and SiC, the cubical model was investigated for them. The results of the simulations show that, the efficiency of AlN betavoltaic nuclear battery is 24 % more than GaN betavoltaic nuclear battery efficiency and 975 % more than SiC betavoltaic nuclear battery efficiency. Also, the efficiency of the AlN betavoltaic nuclear battery (simulated in this work) is about 130 % more than the efficiency of the GaN betavoltaic nuclear battery calculated by others.