600 °C Ultraviolet Photodetector Array With Dual-Peak Responsivity Enhanced by SiGaO x -Engineered β-Ga 2 O 3 /4H-SiC Heterojunction

In this article, we demonstrate a high-temperature ultraviolet (UV) photodetector (PD) array based on a $\beta $ -Ga₂O₃/4H-SiC homotypic (n-type) heterojunction, where the spontaneously formed SiGaO_x interfacial layer plays a pivotal role in suppressing dark current and enhancing photocurrent, enabling stable operation from room temperature (RT) up to $600~^{\circ }$ C. Owing to the complementary absorption of $\beta $ -Ga₂O₃ and 4H-SiC, the PD exhibits a distinct dual-peak spectral response over the entire temperature span. As a result, the device achieves markedly improved responsivity, reaching 1.46 A/W at RT and 10.1 A/W at $600~^{\circ }$ C under 250-nm illumination, and 0.26 and 0.78 A/W under 310-nm illumination, respectively. Furthermore, an $8\times 8$ UV PD array demonstrates imaging capability at $600~^{\circ }$ C. These findings highlight the critical role of the SiGaO_x interfacial layer in $\beta $ -Ga₂O₃/4H-SiC heterojunctions and the potential of such heterojunction structures for UV detection and imaging in extreme-temperature environments.