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Title: Spatially Composition-­graded Monolayer WSe2xTe2−2x Nanosheets
Alloying in two-dimensional (2D) transition metal dichalcogenides (TMD) has allowed bandgap engineering and phase transformation, which provide more flexibility and functionality for electronic and photonic devices. To date, many ternary TMD alloys with homogenous compositions have been synthesized. However, realization of bandgap modulation spatially within a single TMD nanosheet remains largely unexplored. In this work, we demonstrate the synthesis of spatially composition-graded WSe2xTe2-2x flakes using an in situ chemical vapor deposition method. The photoluminescence and Raman spectra line-scanning characterization indicate a spatially graded bandgap, which increases from 1.46 eV (center) to 1.61 eV (edge) within one monolayer flake. Furthermore, the electronic devices based on this spatially graded material exhibit tunable transfer characteristics.  more » « less
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52th IEEE Semiconductor Interface Specialists Conference
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National Science Foundation
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  1. Abstract

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