GaN PIN betavoltaic nuclear batteries are demonstrated in this work. GaN epitaxial layers were grown on 2-inch sapphire sub-strates by MOCVD, and then the GaN PIN nuclear batteries were fabricated. Current-voltage （l-V） characteristic shows that the small leakage currents are 0.12 nA at 0 V and 1.76 nA at -10 V, respectively. With 147Pm the irradiation source, the maximum open circuit voltage and maximum short circuit current are 1.07 V and 0.554 nA, respectively. The fill factor （FF） of 24.7% for the battery was been obtained. The limited performance of the devices is mainly due to the low energy deposition in the microbatteries. Therefore, the GaN nuclear microbatteries are expected to be optimized by growing high quality GaN films, thin dead layer and so on.
