Low-temperature growth of MoS₂ on polymer and thin glass substrates for flexible electronics

Recent advances in two-dimensional semiconductors, particularly molybdenum disulfide (MoS₂), have enabled the fabrication of flexible electronic devices with outstanding mechanical flexibility. Previous approaches typically involved the synthesis of MoS₂ on a rigid substrate at a high temperature followed by the transfer to a flexible substrate onto which the device is fabricated. A recurring drawback with this methodology is the fact that flexible substrates have a lower melting temperature than the MoS₂ growth process, and that the transfer process degrades the electronic properties of MoS₂. Here we report a strategy for directly synthesizing high-quality and high-crystallinity MoS₂ monolayers on polymers and ultrathin glass substrates (thickness ~30 µm) at ~150 °C using metal-organic chemical vapour deposition. By avoiding the transfer process, the MoS₂ quality is preserved. On flexible field-effect transistors, we achieve a mobility of 9.1 cm² V^-1 s^-1 and a positive threshold voltage of +5 V, which is essential for reducing device power consumption. Moreover, under bending conditions, our logic circuits exhibit stable operation while phototransistors can detect light over a wide range of wavelengths from 405 nm to 904 nm.