AFM and temperature-dependent photoluminescence studies of the degree of localization induced by quantum-dot like states in InGaN single quantum well light emitting diodes grown by MOCVD on (0001) sapphire

Florescu, D. I.; Ramer, J.; Merai, V.; Parekh, A.; Lu, Dongzhu; Lee, D.S.; Armour, E.

doi:10.1016/j.jcrysgro.2004.08.076

Cited by 9 publications

(5 citation statements)

References 9 publications

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“…The occupation of higher energy states starts at higher temperatures compared to c-plane quantum wells. In most c-plane GaInN quantum well structures, these temperatures are well below 150 K [30][31][32]. This points to stronger charge carrier localization in the studied m-plane quantum wells.…”

Section: Evidence For Strong Localizationmentioning

confidence: 84%

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Netzel¹,

Mauder²,

Wernicke³

et al. 2011

Semicond. Sci. Technol.

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The development of GaInN quantum well structures with nonpolar crystal orientation for light-emitting diodes and semiconductor lasers is currently one of the main foci of III-nitride-based optoelectronics research. One of the advantages of nonpolar orientations is the absence of polarization fields perpendicular to the quantum well plane. As a consequence, radiative recombination rates are higher compared to quantum wells on polar surfaces. However, due to high densities of threading dislocations and basal plane stacking faults in the case of heteroepitaxially grown nonpolar layers, and due to band gap inhomogeneities in the GaInN quantum wells, characterization of radiative and nonradiative recombination mechanisms is a complex challenge. So far, most published data about band gap fluctuations, charge carrier localization and internal quantum efficiency in nonpolar quantum wells are ambiguous. Here, we present temperature and excitation power density-dependent photoluminescence data featuring multiple characteristics related to strong charge carrier localization in m-plane (1-100) GaInN quantum wells. Thermally activated redistribution of charge carriers between localization sites in these quantum wells is weaker than in polar c-plane ones. The localization strength increases with higher indium concentration in the quantum wells. In the heteroepitaxially grown quantum well structures, the internal quantum efficiency is reduced even at low temperatures (T = 10 K) and especially for m-plane quantum wells with high indium mole fractions.

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Section: Evidence For Strong Localizationmentioning

confidence: 84%

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Netzel¹,

Mauder²,

Wernicke³

et al. 2011

Semicond. Sci. Technol.

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“…This indicated that the dark regions were mainly caused by defects of the nano samples. These defects included threading and misfit dislocations, which could have also enhanced the In incorporation [ 27 , 31 ]. In the planar one, the micro-sized clusters might be due to carrier delocalization, strain, and defects, while the large blueshift of 13.5 nm in Figure 2 b showed the effective strain relaxation of nano-arrays [ 33 , 34 ].…”

Section: Resultsmentioning

confidence: 99%

“…These excessive peaks appeared clearly when the epi-structures were etched down to n-GaN. Furthermore, the threading dislocations (TDs) in the dark region also affected the shallow well’s growth, which caused inhomogeneity and more In incorporation [ 31 ].…”

Section: Resultsmentioning

confidence: 99%

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A Novel Way to Fill Green Gap of GaN-Based LEDs by Pinning Defects in Nanorod Array

et al. 2022

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Nanorod array and planar green-emission InGaN/GaN multi-quantum well (MQW) LEDs were fabricated by lithography, nano-imprinting, and top–down etching technology. The defect-pinning effect of the nanostructure was found for the first time. The ratio of the bright regions to the global area in the panchromatic CL images of green MQW samples increased from 30% to about 90% after nano-fabrication. The overall luminous performance significantly improved. Throughout temperature-dependent photoluminescence (TDPL) and time-resolved PL (TRPL) measurements, the migration and recombination of carriers in the MQWs of green LEDs were analyzed. It was proved that nanostructures can effectively prevent carriers from being captured by surrounding nonradiative recombination centers. The overall PL integral intensity can be enhanced to above 18 times. A much lower carrier lifetime (decreasing from 91.4 to 40.2 ns) and a higher internal quantum efficiency (IQE) (increasing from 16.9% to 40.7%) were achieved. Some disputes on the defect influence were also discussed and clarified.

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“…In single quantum-well structures used for LEDs, Florescu et al [19] reported, for the 3 nm wells containing approximately 15% InN, 3D, i.e., S-K, growth, giving much enhanced 300 K PL intensities. The effects of an inhomogeneous distribution of In on optical properties and device performance will be discussed below.…”

Section: Importance Of Nanostructures For Alingan Alloysmentioning

confidence: 99%

Use of Nanostructures for High Brightness Light-Emitting Diodes

Stringfellow

2011

Energy Efficiency and Renewable Energy Through Nanotechnology

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Light-emitting diodes or LEDs are expected to play a major role in efforts to utilize less energy for lighting applications due to their high efficiency, long operating life, and other ''green'' characteristics. The history of LEDs began in the 1960s. Since that time, the performance has increased exponentially while the cost has decreased dramatically. LEDs dominate the market for monochromatic displays and indicators, and are slated to provide an increasing share of the white light market. During the last decade, advances in efficiency have been obtained partly as a result of the use of nanotechnology. LEDs and lasers provided some of the first applications for quantum-well structures with nm dimensions. Future advances will almost certainly be linked to advances in the use of quantum wire and quantum dot structures. They appear to offer attractive new alternatives for single-junction white light generation. The use of self-assembled structures also offers the promise of allowing the fabrication of high efficiency devices in highly defected materials, such as those grown on less expensive substrates. This chapter reviews the basic aspects of LED devices and materials, with a focus on the AlGaInP system for red and yellow emitters and AlGaInN for blue, green, and white emitters, all grown by the organometallic vapor phase epitaxial technique. The focus is on the present and future use of nanotechnology for lighting applications.

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AFM and temperature-dependent photoluminescence studies of the degree of localization induced by quantum-dot like states in InGaN single quantum well light emitting diodes grown by MOCVD on (0001) sapphire

Cited by 9 publications

References 9 publications

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

Strong charge carrier localization interacting with extensive nonradiative recombination in heteroepitaxially grown m-plane GaInN quantum wells

A Novel Way to Fill Green Gap of GaN-Based LEDs by Pinning Defects in Nanorod Array

Use of Nanostructures for High Brightness Light-Emitting Diodes

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