Prospective emission efficiency and in-plane light polarization of nonpolar m-plane InxGa1−xN∕GaN blue light emitting diodes fabricated on freestanding GaN substrates

• Published in: Applied physics letters 2006-08, Vol.89 (9)
• Main Authors: Koyama, T., Onuma, T., Masui, H., Chakraborty, A., Haskell, B. A., Keller, S., Mishra, U. K., Speck, J. S., Nakamura, S., DenBaars, S. P., Sota, T., Chichibu, S. F.
• Format: Article
• Language: English
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.2337085

Prospective equivalent internal quantum efficiency (ηint) of approximately 34% at 300K was demonstrated for the blue emission peak of nonpolar m-plane (11¯00) InxGa1−xN∕GaN multiple quantum well light emitting diodes (LEDs) fabricated on freestanding m-plane GaN substrates. Although the ηint value is yet lower than that of conventional c-plane blue LEDs (>70%), the results encourage one to realize high performance green, amber, and red LEDs by reducing the concentration of nonradiative defects, according to the absence of the quantum-confined Stark effects due to the polarization fields parallel to the quantum well normal. The electric field component of the blue surface emission was polarized perpendicular to the c axis with the in-plane polarization ratio of 0.58 at 300K.