Circularly Polarized Luminescence in Zero-Dimensional Antimony Halides: Structural Distortion Controlled Luminescence Thermometer

Materials
emitting circularly polarized luminescence (CPL) have
been intensively studied for their promising applications in various
fields. However, developing tunable and responsive CPL materials in
a wide wavelength range remains a great challenge. Here, a pair of
chiral (R,R/S,S-DCDA)3Sb2Cl12 (DCDA = dimethyl-1,2-cyclohexanediamine divalent cation) shows
efficient broadband yellow emission with a photoluminescence (PL)
quantum yield of 27.6% with a CPL asymmetry factor of 3 × 10–3. The associated chiroptical activity is attributed
to the efficient chiral transfer as well as the self-trapped exciton
emission originating from the large distortion of the inorganic blocks.
Notably, (R,R/S,S-DCDA)3Sb2Cl12 exhibits a large red-shift emission exceeding 100 nm upon lowering
temperature. An excellent linear correlation of the PL wavelength
on temperature indicates that the compounds can be used as PL thermometers,
which originates from a temperature-dependent linear structural distortion
of the [SbCl6] emitter. This work inspires the potential
utilization of CPL-emitting materials as responsive light sources.