Multi-Color Quantum Well Based LEDs



High-efficiency InGaN based quantum wells (QWs) light-emitting diodes (LEDs) and laser diodes (LDs) play an important role in solid state lighting and display applications. However, it is still challenging to achieve high-efficiency InGaN QWs LEDs and LDs emitting in the deep green and yellow regimes. This is due to the increase of the electrostatic fields in InGaN QW leading to the reduction of the electron-hole wave functions overlap and high threading dislocation density and phase separation in high In-content InGaN QW resulting poor material quality and high nonradiative recombination.


Lehigh University proposes a new method to achieve enhancement of the electron-hole wave functions overlap and emission wavelength red-shift by inserting an InN delta (d)-layer inside the InGaN QW, to form a 3-layer staggered InGaN / delta-InN QW structure. By inserting the narrow band gap InN delta-layer in the InGaN QW, the electron and hole wave functions are pulled toward the center of the InGaN QW, the electron-hole wave functions overlap is significantly enhanced. In addition, the large band offset between the InN delta-layer and the InGaN QW extends the emission wavelength.


Lehigh Tech ID# 072709-02



The SSL market is predicted to reach $33 billion by 2013, growing annually at over 10%.[1] This market is an umbrella market for LEDs, OLEDs, and PLEDs. LED technologies make up a majority of this market ($5.08 billion), with a growth rate of over 24%.[2] Additionally, 22% of the United States electricity is consumed by lighting, which costs consumers over $50 billion each year. SSL technologies have the potential to reduce this consumption by up to six times less. This potential has led to increased market need, funding resources and science centers dedicated to SSL developments, such as the $46 million Energy Frontier Research Center (EFRC) for solid-state lighting science funded by the Department of Energy.[3]

[1] “Solid-State Lighting Market Will Reach $33 Billion Worldwide by 2013.” web site. (accessed September 28, 2010).

[2] About Us.” GE Lumination web site. (accessed September 28, 2010).

[3] Solid-state lighting's contributions to national energy efficiency discussed at AAAS meeting.” February 21, 2010. PHYSORG web site. (accessed

September 28, 2010).



Lehigh University is interested in identifying an industry partner to license this technology. 

App Type Country Serial No. Patent No. File Date Issued Date Expire Date
Utility United States 12/968,960 12/15/2010    
For Information, Contact:
Yatin Karpe
Associate Director
Lehigh University
Nelson Tansu
Hongping Zhao
Guangyu Liu