A betavoltaic microcell based on Au/s-SWCNTs/Ti Schottky junction

•Present a novel betavoltaic microcell based on Au/s-SWCNTs/Ti structure.•Use Ni-63 as the beta particles source.•Single-walled carbon nanotubes fabricated by dielectrophoretic (DEP) method.•Metallic nanotubes are electrically eliminated by high current.•Betavoltaic microcell with Voc of 26 mV, Jsc of 2.19 μA/cm2, and efficiency of 5.20%.

This paper reports a new type betavoltaic (BV) microcell based on intrinsic p-type semiconductive single-walled carbon nanotubes (s-SWCNTs). Our device composes of Au and Ti asymmetrical electrode pairs with s-SWCNTs laid over them forming Schottky junction with Ti and ohmic contact with Au. SWCNT bundles were self-assembled between Au and Ti electrodes by Dieletrophoretic (DEP) technique, and metallic SWCNTs (m-SWCNTs) were selectively eliminated by current-induced electrical breakdown method. 3.3 mCi/cm2 thin-film radioisotope 63Ni serves as beta particles source, with 100-year half-time and low toxicity. Test results show that SWCNTs BV microcell has the open circuit voltage (VOC) of 26 mV, short circuit current density (JSC) of 2.19 μA/cm2 and energy conversion efficiency (η) of 5.20%.