Resolving the Spatial Variation and Correlation of Hyperfine Spin Properties in Organic Light-Emitting Diodes

Area of Science:

• Quantum materials science
• Organic electronics
• Spintronics

Background:

• Organic materials offer tunable spin properties for quantum technologies.
• Progress in quantum information processors and sensors is significant.
• Challenges remain in scaling organic quantum devices due to property variations.

Purpose of the Study:

• To map the hyperfine spin property, the Overhauser field, in organic light-emitting diodes (OLEDs).
• To investigate intra-device variations in quantum properties.
• To understand spatial correlations of these properties for device integration.

Main Methods:

• Utilized spatially resolved magnetoluminescence.
• Generated the first 2D map of the Overhauser field in OLEDs.
• Analyzed intra-device variability and spatial correlation of spin properties.

Main Results:

• Demonstrated significant intra-device variabilities exceeding approximately 30% in the Overhauser field.
• Observed spatially correlated behavior on length scales greater than 7 µm.
• Identified variations comparable to the size of pixels in active-matrix OLED arrays.

Conclusions:

• Intra-device variations in organic quantum properties pose challenges for reproducibility and integration.
• Spatial correlations suggest limitations for scaling to smaller, high-resolution quantum devices.
• Findings have implications for the design and fabrication of future organic quantum technologies.