Up-conversion photoluminescence of transition metal chalcogenide monolayers under high pressure

Abstract The up-conversion photoluminescence (UPL) phenomena of transition metal chalcogenides (TMDCs) materials have been studied in the recent years, but high-pressure tuning effect remains unclear. In this work, we applied pressure to the monolayer WS 2 by Diamond Anvil Cell (DAC). The PL and UPL of monolayer WS 2 under ambient pressure and tuning from 0.96GPa to 4.48GPa were investigated using various excitation energies. We found that with the increase of applied pressure, the intensity of UPL decreased dramatically. Under the same pressure, the peak of UPL is shifted compared with that of normal PL. This tuning is promising for realizing photodetection by using of the up-conversion process.