Open AccessStudy of efficient semipolar (11-22) InGaN green micro-light-emitting diodes on high-quality (11-22) GaN/sapphire template
Author(s) -
Hongjian Li,
Matthew S. Wong,
Michel Khoury,
Bastien Bonef,
Haojun Zhang,
YiChao Chow,
Panpan Li,
Jared Kearns,
Aidan A. Taylor,
P. de Mierry,
Z. Hassan,
Shuji Nakamura,
Steven P. DenBaars
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.024154
Subject(s) - materials science , light emitting diode , optoelectronics , sapphire , indium , passivation , diode , quantum well , indium gallium nitride , quantum efficiency , chemical vapor deposition , wavelength , substrate (aquarium) , gallium nitride , optics , layer (electronics) , laser , nanotechnology , oceanography , physics , geology
We investigated the electrical and optical performances of semipolar (11-22) InGaN green µLEDs with a size ranging from 20 × 20 µm 2 to 100 × 100 µm 2 , grown on a low defect density and large area (11-22) GaN template on patterned sapphire substrate. Atom probe tomography (APT) gave insights on quantum wells (QWs) thickness and indium composition and indicated that no indium clusters were observed in the QWs. The µLEDs showed a small wavelength blueshift of 5 nm, as the current density increased from 5 to 90 A/cm 2 and exhibited a size-independent EQE of 2% by sidewall passivation using atomic-layer deposition, followed by an extremely low leakage current of ~0.1 nA at -5 V. Moreover, optical polarization behavior with a polarization ratio of 40% was observed. This work demonstrated long-wavelength µLEDs fabricated on semipolar GaN grown on foreign substrate, which are applicable for a variety of display applications at a low cost.