NaYF4:Yb,Er-MoS2: from synthesis and surface ligand stripping to negative infrared photoresponse

The synthesis, surface ligand stripping, and infrared optoelectronic device application of NaYF4:Yb,Er-MoS2 nanocomposites are reported. NaYF4:Yb,Er-MoS2 film shows an unusual negative infrared photoresponse after SOCl2/DMF treatment, which exhibits more than two times the photoresponsivity of pure NaYF4:Yb,Er, showing great potential for the development of novel infrared optoelectronic devices.