LAUSR

Abstract Large-area monolayer WS2 triangles with an average lateral dimension of ~60 μm were grown by chemical vapor deposition (CVD) and a Raman study on the carrier concentration is presented. With temperature-dependent Raman spectra measured over a temperature range of 3 to 520 K, it indicates that the full width at half maximum and intensity of A1g mode were strongly affected by the carrier concentration and corresponding electron-phonon coupling, while the E12g mode was less influenced. In the position-dependent Raman spectra, an increasing number of charge carriers were also discovered along the growth direction. And an upward energy band bending and impurities adsorption were found in the edge regions, which should be taken into consideration for improving the performance of monolayer growth.