Characterization of Thin GaN Layers Deposited by Hydride Vapour Phase Epitaxy (HVPE) on 6H- SiC Substrates

2000 ◽  
Vol 622 ◽  
Author(s):  
J.T. Wolan ◽  
Y. Koshka ◽  
S.E. Saddow ◽  
Yu. V. Melnik ◽  
V. Dmitriev

ABSTRACTIn this study, the near-surface regions of air-exposed thin GaN layers deposited by hydride vapour phase (HVPE) epitaxy on 6H-SiC substrates have been examined. Chemical-state identification and in-depth elemental distribution profiles are evaluated using angle-resolved X-ray photoelectron spectroscopy (ARXPS) and secondary ion mass spectroscopy (SIMS). The epilayers show a high degree of chemical purity as determined by XPS and SIMS. Low temperature photoluminescence (PL) were performed and is dominated by donor-acceptor pairs (DAP) emission. Layer thickness was measured to be ∼ 600-700 nm and an abrupt, well-defined heterointerface is observed using scanning electron microscopy (SEM) and SIMS.

Author(s):  
A. Carlsson ◽  
J.-O. Malm ◽  
A. Gustafsson

In this study a quantum well/quantum wire (QW/QWR) structure grown on a grating of V-grooves has been characterized by a technique related to chemical lattice imaging. This technique makes it possible to extract quantitative information from high resolution images.The QW/QWR structure was grown on a GaAs substrate patterned with a grating of V-grooves. The growth rate was approximately three monolayers per second without growth interruption at the interfaces. On this substrate a barrier of nominally Al0.35 Ga0.65 As was deposited to a thickness of approximately 300 nm using metalorganic vapour phase epitaxy . On top of the Al0.35Ga0.65As barrier a 3.5 nm GaAs quantum well was deposited and to conclude the structure an additional approximate 300 nm Al0.35Ga0.65 As was deposited. The GaAs QW deposited in this manner turns out to be significantly thicker at the bottom of the grooves giving a QWR running along the grooves. During the growth of the barriers an approximately 30 nm wide Ga-rich region is formed at the bottom of the grooves giving a Ga-rich stripe extending from the bottom of each groove to the surface.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agata Bojarska-Cieślińska ◽  
Łucja Marona ◽  
Julita Smalc-Koziorowska ◽  
Szymon Grzanka ◽  
Jan Weyher ◽  
...  

AbstractIn this work we investigate the role of threading dislocations in nitride light emitters with different indium composition. We compare the properties of laser diodes grown on the low defect density GaN substrate with their counterparts grown on sapphire substrate in the same epitaxial process. All structures were produced by metalorganic vapour phase epitaxy and emit light in the range 383–477 nm. We observe that intensity of electroluminescence is strong in the whole spectral region for devices grown on GaN, but decreases rapidly for the devices on sapphire and emitting at wavelength shorter than 420 nm. We interpret this behaviour in terms of increasing importance of dislocation related nonradiative recombination for low indium content structures. Our studies show that edge dislocations are the main source of nonradiative recombination. We observe that long wavelength emitting structures are characterized by higher average light intensity in cathodoluminescence and better thermal stability. These findings indicate that diffusion path of carriers in these samples is shorter, limiting the amount of carriers reaching nonradiative recombination centers. According to TEM images only mixed dislocations open into the V-pits, usually above the multi quantum wells thus not influencing directly the emission.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Koperski ◽  
K. Pakuła ◽  
K. Nogajewski ◽  
A. K. Dąbrowska ◽  
M. Tokarczyk ◽  
...  

AbstractWe demonstrate quantum emission capabilities from boron nitride structures which are relevant for practical applications and can be seamlessly integrated into a variety of heterostructures and devices. First, the optical properties of polycrystalline BN films grown by metalorganic vapour-phase epitaxy are inspected. We observe that these specimens display an antibunching in the second-order correlation functions, if the broadband background luminescence is properly controlled. Furthermore, the feasibility to use flexible and transparent substrates to support hBN crystals that host quantum emitters is explored. We characterise hBN powders deposited onto polydimethylsiloxane films, which display quantum emission characteristics in ambient environmental conditions.


2007 ◽  
Vol 18 (6) ◽  
pp. 065606 ◽  
Author(s):  
T Yatsui ◽  
J Lim ◽  
T Nakamata ◽  
K Kitamura ◽  
M Ohtsu ◽  
...  

1998 ◽  
Vol 184-185 ◽  
pp. 1338 ◽  
Author(s):  
D.N. Gnoth ◽  
T.L. Ng ◽  
I.B. Poole ◽  
D.A. Evans ◽  
N. Maung ◽  
...  

1996 ◽  
Vol 05 (04) ◽  
pp. 621-629 ◽  
Author(s):  
J. VALENTA ◽  
D. GUENNANI ◽  
A. MANAR ◽  
P. GILLIOT

The detailed characterization of metal organic vapour phase epitaxy grown ZnS layers on GaAs is the first step towards the study of their different non-linear optical properties performed with nanosecond lasers. Biexciton phenomena (with a binding energy of about 10 meV) are observed in photoluminescence-excitation and optical-gain spectra.


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