Yb/Er Coordinatively Doping In Bilayer Wse2 For Fascinating Up-Conversion Luminescence

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 WSe2 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 WSe2 excited by 980 nm laser. The up-conversion luminescence peak at 550 nm originates from Er3+ energy level transition S-4(3/2)-> I-4(15/2). Furthermore, a modulated visible electroluminescence is probed from the LED with architecture of Cr/Au electrodes on Yb-Er co-doped bilayer WSe2/monolayer MoSe2 van der waals heterostructure. Unveiling up conversion luminescence in TMDCs opens a novel way of utility in photomedicine, infrared thermometer, and infrared photography, etc.