Synthesis, Characterization, and Device Application of Antimony-Substituted Violet Phosphorus: A Layered Material.

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 2D materials and explore their properties. Here, we report the synthesis of a layered material, P20.56(1)Sb0.44(1), with a systematic study on characterizations and device applications. This material demonstrates a direct band gap of around 1.67 eV. Using a 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 P20.56(1)Sb0.44(1) flakes with a thickness down to a few nanometers. Interestingly, these field effect transistors show strong photoresponse within the wavelength range of visible light. At room temperature, we have achieved good mobility values (up to 58.96 cm2/V·s), a reasonably high on/off current ratio (∼103), and intrinsic responsivity up to 10 μA/W. Our results demonstrate the potential of P20.56(1)Sb0.44(1) thin flakes as a two-dimensional material for applications in visible light detectors.