Regensburg 2010 – scientific programme

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O: Fachverband Oberflächenphysik

O 69: Symposium Polarization Field Control in Group-III-Nitrides

O 69.2: Invited Talk

Thursday, March 25, 2010, 10:00–10:30, H1

Green light-emitting diodes and laser heterostructures on semi-polar GaN(11-22)/sapphire substrates — •Andre Strittmatter — Palo Alto Research Center, Palo Alto, CA, USA

The performance of nitride-based light emitting diodes (LED) and laser diodes (LD) is subject to polarization charges at the interfaces between the quantum well active region and surrounding barrier material. Reduction or even elimination of such interface charges will enable improved light emitters with power-independent emission wavelength and increased internal quantum efficiency. Different strategies exist to reduce or even eliminate the strength of polarization fields in nitride semiconductor light emitting heterostructures. However, for their potential application within device structures further issues such as strain relaxation, In incorporation and material quality due to the growth itself need to be considered. Semi-polar (11-22) oriented heterostructures offer high In incorporation, low polarization fields in InGaN/GaN quantum wells plus reduced cracking vulnerability of thick AlGaN layers which makes them attractive for long wavelength LEDs and LDs. Experimental results are presented demonstrating reduced blue-shift of long-wavelength emitters and lasing at 500 nm.