Wide-bandgap Ga2O3 single crystal-based heterojunctions with organic interlayers for high-performance x-ray detection

Gallium oxide (Ga2O3) exhibits significant potential for next-generation x-ray detection due to its excellent optoelectronic properties. However, x-ray detectors based on β-Ga2O3 single crystals scarcely reported, mainly because fabricating p-type Ga2O3 remains challenging. In this work, unintentionally doped and Fe-doped β-Ga2O3 single crystal wafers have been systematically investigated for x-ray detection using a heterojunction strategy with organic interlayers. The device performance has been carefully evaluated, achieving high response speed (<0.1 s), low dark current (0.42 nA at −40 V), excellent device stability (stable photoresponse over 6 days of continuous operation), and relatively high x-ray sensitivity (20.7 μC Gy−1 cm−2 for the Fe-doped device). Furthermore, the reduced oxygen vacancy concentration can improve the photocurrent/dark current ratio of the detector. This study proposes an innovative approach for high-performance x-ray detectors based on β-Ga2O3 single crystals.