Ultrafast Multifunctional Photodetector Based on the NiAl₂O₄/4H-SiC Heterojunction

Solar-blind photodetectors based on wide bandgap semiconductors have recently attracted a lot of interest. Nickel-containing spinel phase oxides, such as NiAl₂O₄, are stable p-type semiconductors. This paper describes a multifunctional solar-blind photodetector based on a NiAl₂O₄/4H-SiC heterojunction that utilizes photovoltaic effects. The position sensitivity reaches a value of 1589.7 mV/mm under 405 nm laser illumination, while the relaxation times of vertical photovoltaic (VPV) effect and lateral photovoltaic (LPV) effect under 266 nm laser illumination are only 0.32 and 0.42 μs, respectively. This junction was used to create a space optical communication system with sunlight having little effect on its optoelectronic properties. The ultrafast photovoltaic relaxation time makes NiAl₂O₄/4H-SiC a promising candidate for self-powered high-performance solar-blind detectors.