Yb/Er coordinatively doping in bilayer WSe_2 for fascinating up-conversion luminescence

摘要

Benefited from the controllable synthesis of large-scale transition metal dichalcogenides (TMDCs),abundant physical properties of TMDC van der waals heterostructures,such as moire-exciton,electrostatic gating effects,interlayer magnetism,are widely reported.In optoelectronic categories,the applications of TMDC van der waals heterostructures involve interlayer exciton lasers,single photon emitters,and light-emitting diodes (LEDs).However,the employment of TMDCs in visible light emitter is still challenging due to their narrow band gap.The up-converted luminescence from TMDCs could be an effective way to achieve this goal,which has been reported rarely.In this work,the rare earth Yb/Er co-doped bilayer WSe_2 of atomic thickness is designed and synthesized using precursor ultrasonic mixing and molten-salt assisted chemical vapor deposition technology.A fascinating up-converted luminescence has been realized on the Yb-Er co-doped bilayer WSe_2 excited by 980 nm laser.The up-conversion luminescence peak at 550 nm originates from Er~(3+) energy level transition ~4S_(3/2)→~4I_(15/2).Furthermore,a modulated visible electroluminescence is probed from the LED with architecture of Cr/Au electrodes on Yb-Er co-doped bilayer WSe_2/monolayer MoSe_2 van der waals heterostructure.Unveiling upconversion luminescence in TMDCs opens a novel way of utility in photomedicine,infrared thermometer,and infrared photography,etc.