Highly stable nickel metal-modified black phosphorus-based photodetectors with enhanced magnetic field-assisted photoresponse

Abstract

The unique physicochemical properties of black phosphorus endow it with great potential for application in the field of photodetection, but its stability problem has been hindering its further development. Here, we synthesized 0D/2D mixed-dimensional heterojunctions of two-dimensional (2D) black phosphorus (Ni/BP) modified by nickel particles using a simple impregnation method; this modification of black phosphorus with metallic nickel sites enhances its stability, carrier transport ability and light absorption ability. Notably, the introduction of nickel magnetic elements helps us to realize the application of photoexcited electron spin polarization, which increases the number of spin-polarized photoexcited carriers under the synergistic effect of an external magnetic field, thus effectively prolonging carrier lifetimes and suppressing the complexation of photoexcited electron–hole pairs. The experimental results show that Ni/BP has higher photoresponse current density (2.1 μA cm⁻²), lower charge transfer resistance, and excellent cycling stability compared to sole BP (0.23 μA cm⁻²) and exhibits superior performance under an external magnetic field, reaching the maximum enhancement (∼40%) at 0.5 V bias. This approach to improve the stability and performance of black phosphorus through magnetic metal modification and manipulation of spin-polarized electrons is an effective strategy to break the material's inherent limitations and construct high-performance BP-based optoelectronic devices.