Formation of highly luminescent cesium bismuth halide perovskite quantum dots tuned by anion exchange.

Cs3Bi2Br9 quantum dots (QDs) with photoluminescence quantum yields (PLQYs) of up to 22% were prepared through the steady binding of octylammonium bromide and oleic acid. Excellent thermal stability and good luminescence properties have been achieved as intrinsic features of the inorganic halide perovskites, as well as the effective passivation of surface trap-states.