Tunable Magnetism and Extraordinary Sunlight Absorbance in Indium Triphosphide Monolayer

Atomically thin two-dimensional (2D) materials have received considerable research interest due to their extraordinary properties and promising applications. Here we predict the mono-layered indium triphosphide (InP3) as a new semiconducting 2D material with a range of favourable functional properties by means of ab initio calculations. The 2D InP3 crystal shows high stability and promise of experimental synthesis. It possesses an indirect band-gap of 1.14 eV and a high electron mobility of 1919 cm2V-1s-1, which can be strongly manipulated with applied strain. Remarkably, the InP3 monolayer suggests tunable magnetism and half-metallicity under hole doping or defect engineering, which is attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure. A semiconductor-metal transition is also revealed by doping 2D InP3 with electrons. Furthermore, mono-layered InP3 exhibits extraordinary optical absorption with significant excitonic effects in the entire range of the visible-light spectrum. All these desired properties render 2D InP3 a promising candidate for future applications in a wide variety of technologies, in particular for electronic, spintronic and photovoltaic devices.