Multiexcitonic Emission in Zero-Dimensional Cs₂ZrCl₆:Sb³⁺ Perovskite Crystals

Area of Science:

• Materials Science
• Solid-State Physics
• Photonic Materials

Background:

• Metal halide perovskites show promise for lighting but their multiexcitonic emission processes are not well understood.
• Self-Trapped Excitons (STEs) are crucial for luminescence in these materials, with both intrinsic host and extrinsic dopant-induced STEs potentially contributing.

Purpose of the Study:

• To investigate the multiexcitonic emission processes in Sb³⁺-doped Cs₂ZrCl₆ perovskite crystals.
• To explore the independent control and dynamic color tuning capabilities arising from host and dopant STEs.

Main Methods:

• Utilized steady-state and transient-state spectroscopy to analyze luminescence properties.
• Employed Density Functional Theory (DFT) calculations to understand the origins of multiexcitonic emission.
• Performed selective excitation experiments by precisely controlling the excitation wavelength.

Main Results:

• Observed double luminescence originating from intrinsic host STEs and dopant-induced extrinsic STEs in Cs₂ZrCl₆:Sb³⁺.
• Demonstrated that host and dopant STEs can be independently charged at specific energy levels.
• Confirmed minimal interactions between host and dopant STEs in the zero-dimensional crystal lattice via DFT calculations.

Conclusions:

• The independent control of host and dopant STEs allows for dynamic color tuning in Cs₂ZrCl₆:Sb³⁺ crystals.
• This color kinetic feature presents significant opportunities for developing multicolor light-emitting devices.
• The findings pave the way for novel applications in multilevel optical data encryption.