Experimental simulation of a diamond betavoltaic battery

Diamond single-crystal Schottky barrier $mip$-structures (metal–intrinsic diamond–$p$-doped diamond) with dimensions of 3 $\times$ 3 and 4.1 $\times$ 4.28 mm are fabricated on the basis of HTHP $p$-diamond and CVD $i$-diamond. The betavoltaic characteristics of the diamond structures are studied using a wide-aperture electron beam with an initial energy of 110 keV, partially scattered on the way to a converter by a 14-$\mu$m-thick aluminum layer and a 17-mm-thick air layer. The maximum generated power reached 2.18 mW (41 mW/cm$^2$) with a conversion efficiency of 2–3%.