Synthesis, Characterization, and Device Application of Antimony-Substituted Violet Phosphorus

Two-dimensional (2D) nanoflakes have emerged as a class of materials that may impact electronic technologies in the near future. A challenging but rewarding work is to experimentally identify new 2D materials and explore the properties of them. Here, we report the synthesis of a new layered material P_20.56Sb_0.44, with systematic study on characterizations and device applications. This material demonstrates a direct bandgap around 1.67 eV. Using laser-cutting method, the thin flakes of this material can be separated into multiple segments. We have also fabricated field effect transistors based on few-layer P_20.56Sb_0.44 flakes with thickness down to a few nanometers. Interestingly, these field effect transistors show strong photoresponse within wavelength range of visible light. Under room temperature, we have achieved good mobility values (up to 43.08 cm²/V●s), reasonably high on/off current ratio (~10⁵), and intrinsic responsivity up to 10 μA/W. Our results demonstrate the potential of P_20.56Sb_0.44 thin flakes as a new two-dimensional material for applications in visible light detectors.