Efficient green emission from (112¯2) InGaN∕GaN quantum wells on GaN microfacets probed by scanning near field optical microscopy

2007 ◽  
Vol 90 (26) ◽  
pp. 261912 ◽  
Author(s):  
Y. Kawakami ◽  
K. Nishizuka ◽  
D. Yamada ◽  
A. Kaneta ◽  
M. Funato ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Near Field ◽  
Green Emission

scholarly journals Nanoscale Characterization of Surface Plasmon-Coupled Photoluminescence Enhancement in Pseudo Micro Blue LEDs Using Near-Field Scanning Optical Microscopy

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 751
Author(s):  
Yufeng Li ◽  
Aixing Li ◽  
Ye Zhang ◽  
Peng Hu ◽  
Wei Du ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Near Field ◽  
Excitation Power ◽  
Localized Surface Plasmon ◽  
Excitation Density ◽  
Multiple Quantum ◽  
Excitation Power Density

The microcave array with extreme large aspect ratio was fabricated on the p-GaN capping layer followed by Ag nanoparticles preparation. The coupling distance between the dual-wavelength InGaN/GaN multiple quantum wells and the localized surface plasmon resonance was carefully characterized in nanometer scale by scanning near-field optical microscopy. The effects of coupling distance and excitation power on the enhancement of photoluminescence were investigated. The penetration depth was measured in the range of 39–55 nm depending on the excitation density. At low excitation power density, the maximum enhancement of 103 was achieved at the optimum coupling distance of 25 nm. Time-resolved photoluminescence shows that the recombination life time was shortened from 5.86 to 1.47 ns by the introduction of Ag nanoparticle plasmon resonance.

scholarly journals Nanoscale Characterization of V-defect in InGaN/GaN QWs LEDs using Near-Field Scanning Optical Microscopy

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 633 ◽  
Author(s):  
Li ◽  
Tang ◽  
Zhang ◽  
Guo ◽  
Li ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Near Field ◽  
Light Output ◽  
Current Injection ◽  
Light Output Power ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

The size of the V-defects in the GaN/InGaN-based quantum wells blue light-emitting diode (LED) was intentionally modified from 50 nm to 300 nm. High resolution photoluminescence and electroluminescence of a single large V-defect were investigated by near-field scanning optical microscopy. The current distribution along the {10-11} facets of the large defect was measured by conductive atomic force microscopy. Nearly 20 times the current injection and dominant emission from bottom quantum wells were found in the V-defect compared to its vicinity. Such enhanced current injection into the bottom part of quantum wells through V-defect results in higher light output power. Reduced external quantum efficiency droops were achieved due to more uniform carrier distribution. The un-encapsulated fabricated chip shows light output power of 172.5 mW and 201.7 mW at 400 mA, and external quantum efficiency drop of 22.3% and 15.4% for the sample without and with large V-defects, respectively. Modified V-defects provide a simple and effective approach to suppress the efficiency droop problem that occurs at high current injection, while improving overall quantum efficiency.

Role of localized and extended electronic states in InGaN/GaN quantum wells under high injection, inferred from near-field optical microscopy

1998 ◽  
Vol 73 (4) ◽  
pp. 493-495 ◽  
Author(s):  
A. Vertikov ◽  
A. V. Nurmikko ◽  
K. Doverspike ◽  
G. Bulman ◽  
J. Edmond
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Near Field ◽  
Electronic States ◽  
High Injection

Spatially resolved photoluminescence in InGaN/GaN quantum wells by near-field scanning optical microscopy

2001 ◽  
Vol 79 (7) ◽  
pp. 976-978 ◽  
Author(s):  
M. S. Jeong ◽  
J. Y. Kim ◽  
Y.-W. Kim ◽  
J. O. White ◽  
E.-K. Suh ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Near Field ◽  
Spatially Resolved ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

scholarly journals Multimode scanning near-field photoluminescence spectroscopy and its application for studies of InGaN epitaxial layers and quantum wells

2018 ◽  
Vol 58 (1) ◽  
Author(s):  
Saulius Marcinkevičius ◽  
Tomas Kristijonas Uždavinys ◽  
Ruslan Ivanov ◽  
Mounir Mensi
Keyword(s):  
Surface Morphology ◽  
Quantum Wells ◽  
Optical Microscopy ◽  
Epitaxial Layer ◽  
Near Field ◽  
Sample Surface ◽  
Localized States ◽  
Photoluminescence Spectra ◽  
Potential Fluctuations ◽  
Spatial Nonuniformity

The paper reviews our recent achievements in developing a multimode scanning near-field optical microscopy (SNOM) technique. The multimode SNOM apparatus allows us to simultaneously measure spatial variations of photoluminescence spectra in the illumination and illumination-collection modes, their transients and sample surface morphology. The potential of this technique has been demonstrated on a polar InGaN epitaxial layer and nonpolar InGaN/GaN quantum wells. SNOM measurements have allowed revealing a number of phenomena, such as the band potential fluctuations and their correlation to the surface morphology, spatial nonuniformity of the radiative and nonradiative lifetimes, as well as the extended band nature of localized states. The combination of different modes enabled measurements of the ambipolar carrier diffusion and its anisotropy.

Spatially Resolved Spectroscopy of Blue and Green InGaN Quantum Wells by Scanning Near-Field Optical Microscopy

2017 ◽  
Vol 255 (5) ◽  
pp. 1700322 ◽  
Author(s):  
Satoshi Kurai ◽  
Renma Mihara ◽  
Genki Nobata ◽  
Kohei Okawa ◽  
Narihito Okada ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Microscopy ◽  
Near Field ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy ◽  
Ingan Quantum Wells
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