Efficient Red Light Emitting Diodes Based on a Zero-Dimensional Organic Antimony Halide Hybrid

Area of Science:

• Materials Science
• Organic Electronics
• Photonic Materials

Background:

• Zero-dimensional (0D) organic metal halide hybrids (OMHHs) show promise for tunable light emission.
• Low conductivity of organic cations hinders their application in electrically driven light-emitting diodes (LEDs).

Purpose of the Study:

• To develop a novel OMHH emitter for efficient LEDs by addressing the conductivity challenge.
• To synthesize and characterize triphenyl(9-phenyl-9H-carbazol-3-yl) phosphonium antimony bromide (TPPcarzSbBr4) for red light emission.

Main Methods:

• Synthesized a new OMHH, TPPcarzSbBr4, by incorporating an electroactive phenylcarbazole group into the phosphonium cation.
• Prepared single crystals and solution-processed thin films of TPPcarzSbBr4.
• Fabricated red LEDs using TPPcarzSbBr4 as the light-emitting layer.

Main Results:

• Achieved a high photoluminescence quantum efficiency (PLQE) of 93.8% for TPPcarzSbBr4 single crystals.
• Solution-processed TPPcarzSbBr4 thin films exhibited a PLQE of 86.1%.
• Fabricated red LEDs demonstrated a record external quantum efficiency (EQE) of 5.12%, peak luminance of 5957 cd m⁻², and current efficiency of 14.2 cd A⁻¹ for 0D OMHH devices.

Conclusions:

• The developed semiconducting organic cation (TPPcarz+) successfully enables efficient electroluminescence in 0D OMHHs.
• TPPcarzSbBr4 represents a significant advancement for 0D OMHH-based LEDs, offering superior performance.
• This work paves the way for broader applications of OMHHs in optoelectronic devices.