Efficient and Bright Deep-Red Light-Emitting Diodes based on a Lateral 0D/3D Perovskite Heterostructure

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Deep-red light-emitting diodes (LEDs) are crucial for medical therapy and biological imaging due to deep-red photons' tissue penetration.
• Metal-halide perovskites offer potential for bright and efficient electroluminescence but face challenges like Auger and trap-assisted nonradiative recombination.
• Existing perovskite deep-red LEDs struggle with efficiency and brightness.

Purpose of the Study:

• To develop efficient and bright deep-red perovskite LEDs.
• To overcome recombination issues limiting current perovskite LED performance.
• To demonstrate a novel heterostructure for enhanced deep-red light emission.

Main Methods:

• Fabrication of a lateral Cs4PbI6/FAxCs1-xPbI3 (0D/3D) heterostructure.
• Utilizing Cs4PbI6 as low-defect facilitating layers and low-refractive-index grids.
• Characterization of optoelectronic properties and device performance.

Main Results:

• Achieved a peak external quantum efficiency of 21.0% at a high photon flux (1.75 × 10^21 m^-2 s^-1).
• Demonstrated performance nearly two orders of magnitude higher than previously reported high-efficiency deep-red perovskite LEDs.
• Showcased suitability for pulse oximeters with <2% blood oxygen saturation error.

Conclusions:

• The 0D/3D heterostructure effectively reduces nonradiative recombination and enhances light extraction.
• This breakthrough enables highly efficient and bright deep-red perovskite LEDs.
• The developed LEDs show promise for advanced medical diagnostic tools like pulse oximeters.