High-Entropy Double Perovskites with Tailored Multichannel Luminescence.

Area of Science:

• Materials Science
• Solid State Chemistry
• Nanotechnology

Background:

• Entropy engineering is a key strategy for developing advanced metastable materials.
• Metal-halide double perovskites (DPs) offer unique optoelectronic properties but often lack stability.
• Developing robust DPs with tailored functionalities remains a significant challenge.

Purpose of the Study:

• To introduce a facile solution method for synthesizing novel high-entropy metal-halide double perovskites (HE-DPs).
• To investigate the structural, stability, and optical properties of these newly synthesized HE-DPs.
• To explore the potential of HE-DPs for applications in lighting, displays, and sensing.

Main Methods:

• Facile solution synthesis of single crystals of HE-DPs with the formula Cs2MIMIIICI6.
• Structural and elemental analysis using advanced characterization techniques.
• Optical spectroscopy to determine bandgap, emission, and photon upconversion properties.

Main Results:

• Successful synthesis of high-entropy single-phase single crystals with up to five elements at the MIII site.
• Demonstrated enhanced ambient stability of HE-DPs exceeding three months.
• Observed decreased optical bandgap upon MIII site alloying and synergistic optical properties from lanthanide incorporation.

Conclusions:

• The high-entropy strategy is effective for enhancing the stability and tailoring the optical properties of metal-halide double perovskites.
• Lanthanide-containing HE-DPs exhibit multichannel optical outputs, including broadband emission and photon upconversion.
• These robust HE-DPs hold promise for next-generation lighting, display, and sensing technologies.