Direct synthesis of large-area continuous ReS₂ films on a flexible glass at low temperature

Rhenium disulfide (ReS₂) has been attracting attentions due to the direct bandgap regardless of the thickness and anisotropic electrical, mechanical and optical properties deriving from its unique crystal lattice structure. In order to utilize these properties, some synthesis methods of ReS₂ have been studied for electronic applications. However, their results are not suitable for practical applications because of non-uniformity, discontinuity and difficulty of large-area continuous film growth. Here, we report the synthesis method of layer-controlled wafer-scale (7 × 2 cm²) ReS₂ films by chemical vapor deposition with high uniformity and continuity. Especially, we demonstrate successfully a direct synthesis of ReS₂ on a transparent flexible glass substrate at low synthesis temperature (450 °C) without the aid of a catalyst or a plasma enhanced system. The field effect transistors with asgrown ReS₂ films on the flexible glass exhibit typical n-type behavior with low threshold voltage of 0.75 V, high on-off ratio of 105, low subthreshold swing of 260 mV/decade and mobility of 0.13 cm² V-1 S-1. The direct synthesis of ReS₂ films on flexible glass will provide the platform to realize large area transfer-free fabrication of high quality transparent flexible electronic devices.