Characterization of Photonically-Cured Semiconducting WS₂ Films

Tungsten disulfide (WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) is a transition metal dichalcogenide (TMD) that offers a wide range of potential applications given its electrical properties as a direct band gap semiconductor when in its mono-layer form. By using a photonic curing system (PCS), we can anneal thin-film substrates that contain two-dimensional (2D) materials within milliseconds without causing damage usually done by conventional thermal annealing treatments. In this experiment, we fabricate a device with chemically exfoliated WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ink contacted with titanium (Ti) electrodes. The effect of photonic curing on the film’s electrical properties was analyzed for spin-coated WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> inks on a conventional thermally oxidized silicon (SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/Si) substrate. We found that at given PCS conditions, we can increase the conductivity of the spin-cast film by over 200% through the current-voltage (I-V) measurements that were gathered. The Raman and photoluminescence (PL) spectroscopy measurements also reveal an enhancement in the peak positions of the respective peaks after photonically curing the films. Our initial results reveal that the properties of photonically-cured WS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> can be enhanced, which will be useful in applying this emerging semiconducting material to future electronic and optoelectronic devices.