Creating Energy Transfer Pathways in Lead-Free Perovskite Nanocrystals via Dopant Emission Centers for Optical Sensing

Cesium copper halide (CCH) nanocrystals (NCs) have gained significant interest as a Pb-free alternative to conventional cesium lead halide NCs in fabricating LEDs due to their broadband emission. An in-depth analysis of the origin of such broadband emission in colloidal CCH NCs is presented in this work. Further, the effect of introducing Mn as an emission center in CCH by in situ doping facilitates easy energy transfer to analytes exhibiting remarkable picomolar sensitivity (1.86 pM) toward bentazone (analyte) which otherwise was difficult to achieve, even microlevel sensitivity. A mechanism that can predict the success of sensitized dopant emission and guide the design of host–guest combinations has been systematically elucidated.