Manufacturing WSe₂ optoelectronic membrane-based devices using low-cost optical lithography

Two-dimensional transition metal dichalcogenides (TMDCs) such as tungsten diselenide (WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) exhibit exceptional optoelectronic properties that can be explored for sensing applications using simplified device architectures. In this study, we report a WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-based photodetector using minimally complex fabrication processes, including mechanical exfoliation of WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and manual mask alignment for photolithography. The device was characterized through electrical transport measurements under ambient and cryogenic conditions. Illumination-dependent analysis revealed a photocurrent enhancement factor of approximately 10 times when measured in vacuum compared to ambient conditions while at room temperature and equivalent photoexcitation conditions. Our findings through this study, validate the feasibility of fabricating WSe<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>-based devices, including photodetectors, using simplified fabrication methodologies, in contrast to complicated processes such as e-beam lithography. This approach offers potential for the development of cost-effective manufacturing approaches for optoelectronic devices based on two-dimensional materials.