Two-dimensional single-substance phosphor photodetectors: A device mechanism study based on van der Waals electrode contacts

Represented by black phosphorus, elemental phosphorus has become a key participant in the exploration of advanced semiconductor devices, suitable for various photonics and optoelectronic devices in the mid-infrared range. As an allotrope, violet phosphorus exhibits wide bandgap characteristics and has potential applications in the visible light spectrum due to its more complex lattice structure. However, its device performance has been hindered by the large Schottky barrier between violet phosphorus and metals. In recent research, van der Waals interactions have been utilized to create electrical contacts between two-dimensional materials and violet phosphorus, effectively shielding the Fermi level pinning effect and achieving high-performance device behavior. Furthermore, combining violet phosphorus with black phosphorus in a vertical heterostructure has led to even higher response speeds, and clarified that it belongs to the first type of heterojunction energy band characteristics.