Alpha particle detection based on low leakage and high-barrier vertical PtOx/β-Ga2O3 Schottky barrier diode

Abstract

High-performance radiation detectors are essential in many sectors spanning medical diagnostics, nuclear control, and particle physics. Ultrawide bandgap semiconductor materials have become one of the most promising candidates due to their excellent performance. Here, based on β-Ga2O3, a Schottky diode-type alpha particle detector was demonstrated. In order to reduce the reverse leakage current of the large-area device, the metal-oxide electrode PtOx was introduced to form high-barrier contacts (1.83 eV) with Ga2O3. The device exhibits a low leakage current density of 63 pA/cm2 at −100 V and apparent energy spectra of 241Am generated alpha particles with an energy of 5.486 MeV at various reverse voltages from −40 to −120 V. The charge collection efficiency (CCE) and energy resolution of the device (at −120 V) are 31.7% and 15.3%, respectively. Meanwhile, the mechanism of interaction between alpha particles and β-Ga2O3 was analyzed, and a 45° oblique incidence was adopted to increase the deposited energy of alpha particles in the depletion region. Furthermore, the differences between actual CCE and theoretical CCE are investigated as guidance for further improving detector performance. This work reveals the great potential and good prospects of Ga2O3 as an economical, efficient, and radiation-resistant ionizing radiation detector.