The invention discloses a parallel type PIN type alpha
irradiation battery and a preparing method thereof to mainly solve the problems that a current nuclear battery is low in energy converting ratio and output power. The parallel type PIN type alpha
irradiation battery comprises an upper PIN junction, a lower PIN junction and alpha
irradiation sources, wherein the upper PIN junction and the lower PIN junction are connected in parallel, the lower PIN junction comprises an N type
ohmic contact electrode, an N type highly-doped 4H-
SiC substrate, an N type lightly-doped epitaxial layer, a P type highly-doped epitaxial layer and a P type
ohmic contact electrode from bottom to top in sequence, the top-to-bottom
structural distribution of the PIN junction is the same as the bottom-to-top
structural distribution of the lower PIN junction, at least two grooves are formed in each PIN junction, and the alpha irradiation sources are placed in the grooves respectively. The two PIN junctions make contact with each other through the P type
ohmic contact electrode, and the upper groove and the lower groove are in mirror symmetry and are communicated with each other. The parallel type PIN type alpha irradiation battery has the advantages that the contact area between the irradiation sources and a
semiconductor is large, the nuclear
raw material utilization rate and the energy collection rate are high, and the output
voltage of the battery is large, and the battery can provide power for a small circuit continuously or can provide power for polar regions, deserts and other areas.