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.