Large Area Fabrication of Semiconducting Phosphorene by Langmuir Blodgett Assembly

TL;DR

This paper introduces a novel Langmuir Blodgett assembly method for fabricating large-area, crystalline phosphorene nanosheets with preserved electronic properties suitable for semiconductor applications.

Contribution

It is the first report of controlled organization of exfoliated phosphorene nanosheets on substrates using a NMP-water mixture in LB assembly.

Findings

Densely aligned, crystalline phosphorene sheets larger than 100 microns.

High current modulation of 10^4 in FET devices at room temperature.

Successful fabrication of large-area semiconducting phosphorene films.

Abstract

Although a considerable number of solvent based methodologies have been developed for exfoliating black phosphorus, so far there are no reports on controlled organization of these exfoliated nanosheets on substrates. Here, for the first time to the best of our knowledge, a mixture of N-Methyl-2-pyrrolidone (NMP) and deoxygenated water is employed as a subphase in Langmuir Blodgett (LB) trough for assembling the nanosheets followed by their deposition on substrates and studied its field effect transistor (FET) characteristics. Electron microscopy reveals the presence of densely aligned, crystalline, ultra-thin sheets of pristine phosphorene having lateral dimensions larger than hundred of microns. Furthermore, these assembled nanosheets retain their electronic properties and show a high current modulation of 10^4 at room temperature in FET devices. The proposed technique provides semiconducting phosphorene thin films that are amenable for large area applications.