Synthesis of uniform two-dimensional MoS_(2) films via thermal evaporation

Two-dimensional(2D)molybdenum disulfide(MoS_(2))holds great potential for various applications such as electronic devices,catalysis,lubrication,anti-corrosion and so on.Thermal evaporation is a versatile thin film deposition technique,however,the conventional thermal evaporation techniques face challenges in producing uniform thin films of MoS_(2) due to its high melting temperature of 1375℃.As a result,only thick and rough MoS_(2) films can be obtained using these methods.To address this issue,we have designed a vacuum thermal evaporation system specifically for large-scale preparation of MoS_(2) thin films.By using K2MoS4 as the precursor,we achieved reliable deposition of uniform polycrystalline MoS_(2) thin films with a size of 50 mm×50 mm and controllable thickness ranging from 0.8 to 2.4 nm.This approach also allows for patterned deposition of MoS_(2) using shadow masks and sequential deposition of MoS_(2) and tungsten disulfide(WS_(2)),similar to conventional thermal evaporation techniques.Moreover,we have demonstrated the potential applications of the obtained MoS_(2) thin films in field effect transistors(FETs),memristors and electrocatalysts for hydrogen evolution reaction(HER).