First principles modeling of pure black phosphorus devices under pressure

Abstract

Black phosphorus (BP) has a pressure-dependent bandgap width and shows the potential for applications as a low-dimensional pressure sensor. We built two kinds of pure BP devices with zigzag or armchair conformation, and explored their pressure-dependent conductance in detail by using first principles calculations. The zigzag BP devices and the armchair BP devices exhibit different conductance–pressure relationships. For the zigzag BP devices conductance is robust against stress when the out-of-plane pressure ratio is less than 15%, and then increases rapidly until the conductive channels are fully opened. For the armchair pure BP devices conductance decreases at first by six orders of magnitude under increasing pressure and then increases quickly with further increase of pressure until the devices enter the on-state. This shows that the pure zigzag BP devices are more suitable for the application as flexible electronic devices with almost constant conductance under small pressure, while armchair BP devices can serve as bidirectional pressure sensors. Real-space distributions of band alignments were explored to understand the different pressure-related properties. We fitted a set of parameters based on the results from the empirical Wentzel–Kramers–Brillouin method, which provides an effortless approximation to quantitatively predict the pressure-related behaviors of large pure BP devices.

Low‐Dimensional Black Phosphorus in Sensor Applications: Advances and Challenges

“…[ 31 ] LDBP is now critical in chemical and biological sensing due to its larger adsorption sites and excellent electronic characteristics. [ 14b ]…”

“…Rong et al. [ 14a ] established two pure BP‐based devices with zigzag or armchair structures that both exhibited the pressure‐related electrical properties of BP materials. The central area of each device consisting of BP displayed a tunable pressure ratio from 0 to 30%.…”

“…Reproduced under the terms of the Creative Commons Attribution License 4.0. [ 14a ] Copyright 2019, The Authors, published by Beilstein‐Institute. C) EPD setup for BP.…”

“…Li et al. [ 14b ] developed ionophore‐functionalized flexible integrated black phosphorus arrays (FIBAs) with excellent selectivities for multiple mixed ion detection ( Figure A,B). Ions selectively penetrated the sensor arrays to detect the influence of strain/stress for ion detection (Figure 10B).…”

“…[ 13 ] LDBP shows considerable potential for application in piezoelectric and other flexible sensors due to its high carrier mobility, wide range of band gap modulation, good strain resistance, and band gap phase transition sensitivity to strain in any direction. [ 14 ] Meanwhile, LDBP‐based detection of biomolecules and gases emerged, with sensitive responses to conductance/resistance changes caused by target substances, owing to the sensors resembling honeycomb fold structures with larger adsorption sites, high current switching ratios, and layer‐dependent band gaps.…”