APPLICATIONS OF TECHNOLOGY:

• Light Emitting Diode (LED) and Organic LED devices for
  
  • Energy-efficient area lighting
• Information displays

ADVANTAGES:

• Improved current efficiency
• Improved light extraction
• Reduced defects in LEDs based on inorganic semiconductors

ABSTRACT:

A Berkeley Lab researcher has invented new LED and OLED devices and fabrication techniques that can lead to improved device efficiencies. For LED devices, the invention permits significant reduction of defects in semiconductors, in particular for wide band-gap light-emitting materials. For OLED devices, the invention enables confined current flow in the device and significantly increases light out-coupling from the light emitting layer. For both LED and OLED devices, the invention provides internal light guiding to enhance efficiency and, thereby, improve device performance.

This technology uses structured approaches to LED and OLED architecture as an alternative to conventional, unstructured multi-layer films for LED and OLED devices. In LEDs, the structured features reduce lattice strain, thus decreasing defects and improving efficiency. Prior to the Berkeley Lab technology, developers of short wavelength LED devices had not found a satisfactory solution to the problem of high defect concentration. This technology uses micro and nanoscale heteroepitaxy to achieve a semiconductor island structure of high crystalline quality for covering the substrate.

Similarly, light extraction, particularly for OLEDs, remains an obstacle to achieving high performance devices. This invention offers a solution based on intrinsic device architecture rather than complicated external optical elements.

STATUS:

• Published PCT Patent Application PCT/US2009/051574 available at www.wipo.int. Available for licensing and collaborative research.

To learn more about licensing a technology from LBNL see http://www.lbl.gov/Tech-Transfer/licensing/index.html.

REFERENCE NUMBER: IB-2230

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• High Performance OLEDs with Air-Stable Nanostructured Electrodes, IB-2231
• Solvent Processed Nanotube Composites, IB-2044