Congratulations to PGR Ben Hogan, who has just published a paper on ‘2D WS2 liquid crystals: tunable functionality enabling diverse applications’ in Nanoscale.
Ben says of his paper:
This paper describes the first observation of a liquid crystal phase for dispersions of two-dimensional tungsten disulfide particles in organic solvents. We detail the synthesis methods used to obtain the liquid crystals. We then characterise them, observing interesting and unexpected dichroism properties some of which can be controlled by the application of a magnetic field. We then demonstrate the first applications of the liquid crystals by producing highly uniform thin films of tungsten disulfide, which are then shown to be useful for developing future terahertz modulation devices. This paper represents the culmination of two and a half years of hard work, and involved collaborations with ITMO University (Russia) and Massachusetts Institute of Technology (USA)
Ben’s publications this year include Photoluminescence from NV− Centres in 5 nm Detonation Nanodiamonds: Identification and High Sensitivity to Magnetic Field and Transmission Properties of FeCl3-Intercalated Graphene and WS2 Thin Films for Terahertz Time-Domain Spectroscopy Applications.
Please see below for the abstract of ‘2D WS2 liquid crystals: tunable functionality enabling diverse applications’.
The first observation of liquid crystalline dispersions of liquid phase-exfoliated tungsten disulfide flakes is reported in a range of organic solvents. The liquid crystals demonstrate significant birefringence as observed in the linear and circular dichroism measurements respectively. In particular, linear dichroism is observed throughout the visible range while broad-band circular dichroism can be observed in the range from 500–800 nm. Under an applied magnetic field of ±1.5 T the circular dichroism can be switched ON/OFF, while the wavelength range for switching can be tuned from large to narrow range by the proper selection of the host solvent. In combination with photoluminescence capabilities of WS2, this opens a pathway to a wide variety of applications, such as deposition of highly uniform films over large areas for photovoltaic and terahertz devices.