Zero-Dimensional Hybrid Indium Halides with Efficient and Tunable White-Light Emissions

Two-dimensional hybrid lead perovskites have attracted
a great
deal of attention in white-light-emitting diodes, but the serious
toxicity of Pb2+ and the limited photoluminescence quantum
yield (PLQY) still restrict further optoelectronic application. To
address these issues, a new combining photon strategy was proposed
to achieve highly efficient broadband white-light emission in a new
family of zero-dimensional (0D) indium halides based on an [InCl6]3– octahedron. Remarkably, these 0D halides
display dual-band white-light emission derived from the synergistic
work of blue- and yellow-light-emitting bands, which can be ascribed
to the radiative recombination of bound excitons in organic cations
and self-trapped excitons in inorganic anions, respectively, based
on spectroscopy and theoretical studies. In-depth first-principles
calculation demonstrates that the increased structural deformability
effectively improves the PLQY from 7.01% to 18.56%. As a proof of
concept, this work provides a profound understanding for advancing
the rational design of novel single-component 0D lead-free halides
as high-performance white-light emitters.