Scalable, Low-cost Fabrication of CVD-grown WSe₂ for Optoelectronic Devices

Monolayer transition metal dichalcogenides (TMDs), including WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> often show unique and exciting optical and electrical features. WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> is well-suited for high-performance optoelectronic devices, such as photodetectors due to its intense photoluminescence properties. This study investigates the production of monolayer WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> using vapor growth approaches and subsequently the fabrication of optoelectronic devices manufactured using low-cost optical lithography. The monolayer membranes were synthesized using low-pressure chemical vapor deposition (LPCVD), which is a method for growing high-quality crystals on dielectric substrates. The use of halide salts allowed tungsten trioxide precursor reduction at lower temperatures, which improved the crystal formation process. Raman and photoluminescence spectroscopy revealed the monolayer nature of the synthesized WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>. Raman peaks were prominent and intense photoluminescence occurred at 1.60 eV. The electrical properties of the manufactured WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> photodetector devices with Ti contacts were evaluated under various situations. Optical lithography was used to create scalable optoelectronic devices from WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> monolayer material through high-throughput approaches such as optical lithography.