All-carbon detector with buried graphite pillars in CVD diamond

A diamond detector of 3D architecture without any metallization is developed for spectroscopy of ionizing radiation and single particles detection. The carbon electrode system was fabricated using a femtosecond infrared laser (\(\lambda \) = 1,030 nm) to induce graphitization on the surface and inside 4.0 \(\times \) 4.0 \(\times \) 0.4 mm\(^{3}\) single-crystal chemical vapor deposition diamond slab, resulting in an array of 84 buried graphite pillars of 30 \(\upmu \)m diameter formed orthogonally to the surface and connected by surface graphite strips. Sensitivity to ionizing radiation with \(^{90}\)Sr \(\upbeta \)-source has been measured for the 3D detector and high charge collection efficiency is demonstrated.