Metal-free ferroelectric halide perovskite exhibits visible photoluminescence correlated with local ferroelectricity.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35731878.
- Also identified by DOI 10.1126/sciadv.abo1621 and PMC identifier 9217093.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Perovskite materials with tunable electronic and structural characteristics can realize various physical properties including electrical/ionic conduction, ferroelectricity, and luminescence. Integrating and coupling these properties in a single perovskite material offer new possibilities for fundamental research and applications. In particular, coupling ferroelectricity and luminescence would enable novel applications. Here, we report that the metal-free ferroelectric perovskite MDABCO (<i>N</i>-methyl-<i>N</i>'-diazabicyclo[2.2.2]octonium)-ammonium triiodide exhibits coupled superior ferroelectricity and visible photoluminescence (PL). Besides strong second-harmonic generation (SHG) associated with its ferroelectricity, MDABCO-ammonium triiodide shows long-lifetime PL at room temperature. Remarkably, the PL intensity depends strongly on the polarization of the excitation light. We found that this anisotropy is coupled to the local crystal orientation that was determined by polarization-resolved SHG. Our results suggest that the anisotropic PL property can be tuned in response to its ferroelectric state via an external field and, thereby, presents a previosuly unobserved functionality in perovskites.