LEDs on HVPE grown GaN substrates: Influence of macroscopic surface features

Rahman, Sk. Shaid-Ur; Leute, Robert A. R.; Wang, Junjun; Meisch, Tobias; Klein, Martin; Scholz, F.; Koyama, Koji; Ishii, Miho; Aida, Hideo

doi:10.1063/1.4890348

Cited by 4 publications

(3 citation statements)

References 12 publications

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“…The main goal of these studies was the evaluation of the quantum efficiency of our semipolar quantum wells for emission wavelengths beyond 500 nm. As reported earlier (), our semipolar LEDs have emitted comparably weak light intensities of about 100μW at 20 mA –much lower than what we obtain on similarly grown c ‐plane LEDs emitting at 430 nm: for those devices using the same device technology, light intensities of more than 4 mW have been obtained at 20 mA () on structures with an estimated internal quantum efficiency around 50%.…”

Section: Introductionsupporting

confidence: 54%

Efficiency studies on semipolar GaInN-GaN quantum well structures

Scholz

Meisch

Elkhouly

2016

Phys. Status Solidi A

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In order to clarify the reasons for the fairly poor electroluminescence (EL) performance of semipolar LED structures grown on patterned sapphire wafers, we have analyzed both, pure photoluminescence (PL) test structures without doping only containing 5 GaInN quantum wells and full EL test structures, all emitting at a wavelength of about 510 nm. Evaluating the PL intensity over a wide range of temperatures and excitation powers, we conclude that such quantum wells possess a fairly large internal quantum efficiency of about 20%. However, on EL test structures containing nominally the same quantum wells, we obtained an optical output power of only about 150μW at an applied current of 20 mA. This may be due partly to some thermal destruction of the quantum wells by the overgrowth with p‐GaN. Even more important seems to be the not yet finally optimized p‐doping of these structures.

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Section: Introductionsupporting

confidence: 54%

Efficiency studies on semipolar GaInN-GaN quantum well structures

Scholz

Meisch

Elkhouly

2016

Phys. Status Solidi A

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“…An oxygen doped AlN nucleation layer () and an in‐situ SiN

_{x}

nanomask () are used for defect reduction. Typical threading dislocation (TD) densities are in the low

10^{8}

^{2}

. An AlGaN layer with 10 % to 12 % Al content of 0.4

μ

m thickness is used as lower waveguide cladding.…”

Section: Methodsmentioning

confidence: 99%

Embedded GaN nanostripes on c‐sapphire for DFB lasers with semipolar quantum wells

Leute

Heinz

Wang

et al. 2015

Physica Status Solidi (b)

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GaN based laser diodes with semipolar quantum wells are typically grown on free‐standing pseudo‐substrates of small size. We present an approach to create a distributed‐feedback (DFB) laser with semipolar quantum wells (QWs) on c‐oriented templates. The templates are based on 2‐inch sapphire wafers, the method could easily be adapted to larger diameters which are available commercially. GaN nanostripes with triangular cross‐section are grown by selective area epitaxy (SAE) and QWs are grown on their semipolar side facets. The nanostripes are completely embedded and can be sandwiched inside a waveguide. For optical pumping, open waveguide structures with only a bottom cladding are used. Using nanoimprint lithography, stripe masks with 250 nm periodicity were fabricated over the whole wafer area. The periodicity corresponds to a 3rd order DFB structure for a laser emitting in the blue wavelength regime. These samples were analyzed structurally by high‐resolution transmission electron microscopy (HRTEM), and spatio‐spectrally by cathodoluminescence (CL) inside a scanning transmission electron microscope (STEM). Samples with an undoped cap are pumped optically for stimulated emission. To prove the feasibility of realizing a 2nd order DFB structure with this approach, stripes with a 170 nm periodicity are fabricated by electron beam lithography and SAE.

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“…Приборные структуры на основе нитрида галлия (GaN), выращенные методом гомоэпитаксии, по своим характеристикам превосходят аналоги, созданные с использованием подложек сапфира, кремния и карбида кремния [1,2]. На данный момент технология промышленного производства подложек GaN отсутствует, поэтому работы над созданием таких подложек являются актуальными и ведутся по нескольким направлениям.…”

Section: поступило в редакцию 7 июня 2016 гunclassified

Буферные Слои Аморфного Углерода Для Отделения Свободных Пленок Нитрида Галлия

Алтахов¹,

Горбунов²,

Кашарина³

et al. 2016

Письма В Журнал Технической Физики

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Исследована возможность использования пленок аморфного алмазоподобного углерода (diamond-like carbon, DLC) для самоотделения слоев нитрида галлия (GaN), выращенного методом хлорид-гидридной газофазной эпитаксии. Пленки DLC были синтезированы методом плазмохимического осаждения при пониженном давлении на подложках сапфира (Al2O3) с кристаллографической ориентацией (0001). Проведены исследования образцов методами комбинационного рассеяния света и рентгеноструктурного анализа. Показано, что тонкие пленки DLC не оказывают существенного влияния на процессы зарождения и роста пленок нитрида галлия. При этом уменьшается прочность границы раздела "пленка GaN-подложка Al2O3", что способствует отделению слоев GaN.

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LEDs on HVPE grown GaN substrates: Influence of macroscopic surface features

Cited by 4 publications

References 12 publications

Efficiency studies on semipolar GaInN-GaN quantum well structures

Efficiency studies on semipolar GaInN-GaN quantum well structures

Embedded GaN nanostripes on c‐sapphire for DFB lasers with semipolar quantum wells

Буферные Слои Аморфного Углерода Для Отделения Свободных Пленок Нитрида Галлия

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