Nonradiative Energy Transfer between Thickness-Controlled Halide Perovskite Nanoplatelets

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Halide perovskite nanostructures show promise for optoelectronics but face commercialization hurdles due to inefficient electrical excitation and high exciton binding energies.
• Förster resonance energy transfer (FRET) offers an efficient pathway for exciton transport, but halide ion migration complicates cascaded structure fabrication.

Purpose of the Study:

• To demonstrate a method for creating cascaded energy transfer structures using halide perovskite nanoplatelets (NPls).
• To exploit quantum confinement effects in two-dimensional (2D) CsPbBr₃-based NPls for efficient energy transfer.

Main Methods:

• Fabrication of thin films using CsPbBr₃-based NPls with two distinct thicknesses.
• Photoluminescence (PL) spectroscopy to analyze energy transfer dynamics.
• Determination of FRET rates and efficiencies.

Main Results:

• Observed enhanced acceptor PL emission and decreased donor PL lifetime in NPl films, indicating FRET.
• Quantified FRET transfer rates up to 0.99 ns^-1 and efficiencies approaching 70%.
• Confirmed FRET occurrence between NPls of varying thicknesses.

Conclusions:

• The quantum confinement effect in 2D CsPbBr₃ NPls facilitates efficient FRET.
• This strategy enables the creation of tailored energy cascade nanostructures.
• The findings pave the way for improved perovskite-based optoelectronic devices.