Pressure-Induced Superconductivity in Sulfur-Doped SnSe Single Crystal Using Boron-Doped Diamond Electrode-Prefabricated Diamond Anvil Cell

A sulfur-doped SnSe single crystal was successfully synthesized by a melt and slow-cooling method. The chemical composition and valence state of the obtained sample were analyzed by X-ray photoelectron spectroscopy. The pressure limitation of a diamond anvil cell with boron-doped diamond electrodes was upgraded to 104 GPa using a nano-polycrystalline diamond anvil to investigate a pressure effect on the sample. Electrical resistivity measurements of the sulfur-doped SnSe single crystal showed the insulator–metal–superconductor transition by applying a high pressure of up to 75.9 GPa.