Emission characteristics of GaInN/GaN multiple quantum shell nanowire-based LEDs with different p-GaN growth conditions

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sae Katsuro ◽  
Weifang Lu ◽  
Kazuma Ito ◽  
Nanami Nakayama ◽  
Naoki Sone ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Light Output ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Current Injection ◽  
Emission Characteristics ◽  
Multiple Quantum ◽  
Plane Region

Abstract Improving current injection into r- and m-planes of nanowires (NWs) is essential to realizing efficient GaInN/GaN multiple quantum shell (MQS) NW-based light-emitting diodes (LEDs). Here, we present the effects of different p-GaN shell growth conditions on the emission characteristics of MQS NW-LEDs. Firstly, a comparison between cathodoluminescence (CL) and electroluminescence (EL) spectra indicates that the emission in NW-LEDs originates from the top region of the NWs. By growing thick p-GaN shells, the variable emission peak at around 600 nm and degradation of the light output of the NW-LEDs are elaborated, which is attributable to the localization of current in the c-plane region with various In-rich clusters and deep-level defects. Utilizing a high growth rate of p-GaN shell, an increased r-plane and a reduced c-plane region promote the deposition of indium tin oxide layer over the entire NW. Therefore, the current is effectively injected into both the r- and m-planes of the NW structures. Consequently, the light output and EL peak intensity of the NW-LEDs are enhanced by factors of 4.3 and 13.8, respectively, under an injection current of 100 mA. Furthermore, scanning transmission electron microscope images demonstrate the suppression of dislocations, triangular defects, and stacking faults at the apex of the p-GaN shell with a high growth rate. Therefore, localization of current injection in nonradiative recombination centers near the c-plane was also inhibited. Our results emphasize the possibility of realizing high efficacy in NW-LEDs via optimal p-GaN shell growth conditions, which is quite promising for application in the long-wavelength region.

scholarly journals Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

2020 ◽  
Author(s):  
Dario Schiavon ◽  
Elżbieta Litwin-Staszewska ◽  
Rafał Jakieła ◽  
Szymon Grzanka ◽  
Piotr Perlin
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Low Temperature ◽  
Surface Morphology ◽  
Growth Temperature ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Pit Formation ◽  
Movpe Growth

The effect of growth temperature and precursor flows on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

Material and Device Characteristics of MBE-Grown GaN Using a New rf Plasma Source

1996 ◽  
Vol 449 ◽  
Author(s):  
R. Beresford ◽  
K. S. Stevens ◽  
Q. Cui ◽  
A. Schwartzman ◽  
H. Cheng
Keyword(s):  
Growth Rate ◽  
Light Output ◽  
Visible Spectrum ◽  
High Growth ◽  
Deep Trap ◽  
Plasma Source ◽  
High Growth Rate ◽  
Rf Plasma ◽  
Energy Separation ◽  
Donor And Acceptor

ABSTRACTA new rf plasma nitrogen source has been characterized for growth of GaN on basal-plane sapphire by molecular beam epitaxy. For rf power of 500 W and N2 flow rate of 2 sccm, a maximum GaN growth rate of 0.80 μm/hr is obtained, implying a source efficiency greater than 5%. It is found that the GaN surface roughness is extremely sensitive to V:Il ratio near unity and independent of growth rate in the range 0.3-0.8 μm/hr. Roughness as small as 1.0 nm (rms) is measured by atomic-force microscopy. Microstructure of the high-growth-rate films is similar to other GaN films, as observed in cross-section transmission electron microscope images. The electroluminescence spectra from homojunction light-emitting diodes exhibit a band of nearultraviolet emissions corresponding to the energy separation of the intentional donor and acceptor levels on the two sides of the junction. The intensity of these emissions relative to the visible spectrum increases with drive current density, implying saturation of deep trap levels responsible for the visible light output.

Limitation of Selective Epitaxial Growth Conditions in Gas Source MBE Using Si2H6

1990 ◽  
Vol 204 ◽  
Author(s):  
Junro Sakai ◽  
Ken-Ichi Aketagawa ◽  
Toru Tatsumi
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Native Oxide ◽  
Initial Growth ◽  
Selective Epitaxial Growth ◽  
Gas Source ◽  
Gas Source Mbe

ABSTRACTLow temperature and high growth rate selective epitaxial growth (SEG) on Si02 patterned Si (001) substrate in gas-source molecular-beam epitaxy (GS-MBE) using pure Si2H6 has been investigated by RHEED observation. In the temperature range of 550 to 850°C, SEG was completely obtained at an initial growth stage. Limiting conditions of SEG were closely related with critical volume of supply gas that was equal to the total amount molecules supplied on SiO2 surface during the incubation period of initial growth. The surface SiO2 was induced to evaporate with Si2H6 supplied above 800°C, so that thermal cleaning temperature for removing native oxide came down to 800°C. As a result, the maximum process temperature of Si SEG now became 800°C, and its growth rate reached as high as 645A/min at growth temperature of 700°C.

scholarly journals Concentrated Chloride-Based Epitaxial Growth of 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 95-98 ◽  
Author(s):  
Anne Henry ◽  
Stefano Leone ◽  
Sven Andersson ◽  
Olof Kordina ◽  
Erik Janzén
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Systematic Study ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Gas Mixture ◽  
Process Pressure ◽  
Order Of Magnitude ◽  
Standard Gas

A chloride-based CVD process has been studied in concentrated growth conditions. A systematic study of different carrier flows and pressures has been done in order to get good quality epilayers on 8° off and on-axis substrates while using very low carrier flows. Hydrogen chloride (HCl) was added to the standard gas mixture to keep a high growth rate and to get homo-polytypic growth on on-axis substrates. The carrier flow was reduced down to one order of magnitude less than under typical growth condition. By lowering the process pressure it was possible to reduce precursor depletion along the susceptor which improved the thickness uniformity to below 2% variation (σ/mean) over a 2” diameter wafer.

High Growth Rate with Reduced Surface Roughness during On-Axis Homoepitaxial Growth of 4H-SiC

2011 ◽  
Vol 679-680 ◽  
pp. 115-118 ◽  
Author(s):  
Jawad ul Hassan ◽  
Peder Bergman ◽  
Anne Henry ◽  
Erik Janzén
Keyword(s):  
Growth Rate ◽  
Surface Roughness ◽  
Surface Morphology ◽  
High Growth ◽  
Lower Surface ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Homoepitaxial Growth ◽  
Order Of Magnitude ◽  
Reduced Surface

The effect of different C/Si ratio on the surface morphology has been studied to optimize the on-axis homoepitaxial growth conditions on 4H-SiC substrates to improve the surface roughness of epilayers. The overall surface roughness is found to decrease with decreasing C/Si ratio. An order of magnitude lower surface roughness has been observed using C/Si ratio = 0.8 without disturbing the polytype stability in the epilayer. A high growth rate of 10 µm/h was achieved without introducing 3C inclusions. The epilayers grown at higher growth rate with C/Si ratio = 1 also had improvements in the surface roughness. 100% 4H polytype was maintained in the epilayers grown with C/Si ratio in the range of 1.2 to 0.8 and with high growth rate of 10 µm/h.

Growth of GaN Nanorods on (0001) Sapphire Substrates by Hydride Vapor Phase Epitaxy

2002 ◽  
Vol 727 ◽  
Author(s):  
Hwa-Mok Kim ◽  
Doo Soo Kim ◽  
Young Wook Chang ◽  
Deuk Young Kim ◽  
Tae Won Kang
Keyword(s):  
Growth Rate ◽  
Vapor Phase ◽  
Substrate Surface ◽  
High Growth ◽  
Average Diameter ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Sapphire Substrates

AbstractGaN nanorods were grown on (0001) sapphire substrates by hydride vapor phase epitaxy HVPE) through a self-assemble process. The nanorods were grown at high growth rate, with the c-axis maintained perpendicular to the substrate surface. The dependence of rod diameter and density on growth conditions was systematically investigated. The average diameter was minimized to 80-120 nm and the density of the GaN nanorods was 100×1012 rods/m2.

scholarly journals Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 354
Author(s):  
Dario Schiavon ◽  
Elżbieta Litwin-Staszewska ◽  
Rafał Jakieła ◽  
Szymon Grzanka ◽  
Piotr Perlin
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Low Temperature ◽  
Surface Morphology ◽  
Growth Temperature ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Pit Formation ◽  
Movpe Growth

The effect of growth temperature and precursor flow on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

Exploring SiC Growth Limitation of Vapor-Liquid-Solid Mechanism when Using Two Different Carbon Precursors

2013 ◽  
Vol 740-742 ◽  
pp. 323-326
Author(s):  
Kassem Alassaad ◽  
François Cauwet ◽  
Davy Carole ◽  
Véronique Soulière ◽  
Gabriel Ferro
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
High Growth Rate ◽  
Carbon Precursor ◽  
Growth Limitation ◽  
Vapor Liquid Solid ◽  
Partial Pressures ◽  
Vapor Liquid Solid Mechanism ◽  
Vls Growth ◽  
Vapor Liquid

Abstract. In this paper, conditions for obtaining high growth rate during epitaxial growth of SiC by vapor-liquid-solid mechanism are investigated. The alloys studied were Ge-Si, Al-Si and Al-Ge-Si with various compositions. Temperature was varied between 1100 and 1300°C and the carbon precursor was either propane or methane. The variation of layers thickness was studied at low and high precursor partial pressure. It was found that growth rates obtained with both methane and propane are rather similar at low precursor partial pressures. However, when using Ge based melts, the use of high propane flux leads to the formation of a SiC crust on top of the liquid, which limits the growth by VLS. But when methane is used, even at extremely high flux (up to 100 sccm), no crust could be detected on top of the liquid while the deposit thickness was still rather small (between 1.12 μm and 1.30 μm). When using Al-Si alloys, no crust was also observed under 100 sccm methane but the thickness was as high as 11.5 µm after 30 min growth. It is proposed that the upper limitation of VLS growth rate depends mainly on C solubility of the liquid phase.

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