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

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 PtO_x 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.