Skip to Content
Find More Like This
Return to Search

Electroluminescent, Multicolor Light Emitting Devices (LEDs)

Lawrence Berkeley National Laboratory

Contact LBL About This Technology

Technology Marketing Summary

A Berkeley Lab research team led by Wladyslaw Walukiewicz has developed an intermediate band solar cell (IBSC) with electrically blocked intermediate band with the ability to emit light of two different photon energies simultaneously.

The IBSC’s unique structure and charge depletion regions make this the first technology capable of electroluminescent emission when applying an electric field with either forward or reverse bias, enabling the device to simultaneously emit light of different color. 

Description

A Berkeley Lab research team led by Wladyslaw Walukiewicz has developed an intermediate band solar cell (IBSC) with electrically blocked intermediate band with the ability to emit light of two different photon energies simultaneously.

The IBSC’s unique structure and charge depletion regions make this the first technology capable of electroluminescent emission when applying an electric field with either forward or reverse bias, enabling the device to simultaneously emit light of different color.

 

The novel device has a GaNAs alloy active region with low percentage of nitrogen, which emits multicolor lights when biased with an electric field. This multicolor emission is possible due to the unique band structure of highly mismatched alloys (HMA), such as GaNAs. With a proper design and an optimized structure multi-colored emissions can be adjusted, and the emission intensity can be amplified.

 

The Berkeley Lab team is the first to provide a direct observation of the optical transition between the charge conducting bands and the intermediate band. The invention opens a possibility to control the color and the intensity of the emitted light through an engineering of the band structure of HMAs, enabling future optimization. Current technologies achieve multicolor effects using separate LEDs, therefore, the ability to emit different photons simultaneously in a single LED device  can be greatly beneficial for the flat panel display industry. 

Benefits
  • Enables emissions of different colors without using separate LEDs
  • Enables control of the emitted light colors through band structure engineering
  • Enables color mixing from a single LED
Applications and Industries
  • Flat panel displays
  • High intensity color displays
  • LED screens
  • Semiconductor emitters and detectors
  • Solar cells
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
2015-147ProposedAvailable02/04/201702/06/2017

Contact LBL About This Technology

To: Suzanne Storar<ipo@lbl.gov>