Properties of GaN Epitaxial Layer Grown by MOVPE on MgAl2O4 Substrate

1995 ◽  
Vol 395 ◽  
Author(s):  
A. Kuramata ◽  
K. Horino ◽  
K. Domen ◽  
R. Soejima ◽  
H. Sudo ◽  
...  

ABSTRACTWe propose a MgAl2O4 substrate for GaN-based laser diodes. We grew GaN epitaxial layers using metal-organic vapor phase epitaxy on a MgAl2O4 substrate. The GaN on the MgAl2O4 showed a narrow X-ray diffraction peak of 310 arcsec, a photoluminescence dominated by the band-edge emission, and good electronic properties. The optical cavity was fabricated by cleaving the GaN on the MgAl2O4, and the stimulated emission from the cavity using optical pumping was observed. We also fabricated a light emitting diode (LED) with a AlGaN/InGaN double-heterostructure. The electroluminescence was dominated by the band-edge emission of InGaN with a narrow FWHM of 13.5 nm. The characteristics of LED on the MgAl2O4 were comparable to that on a A12O3 substrate. MgAl2O4 is feasible as a substrate for laser applications.

1995 ◽  
Vol 395 ◽  
Author(s):  
Hiroshi Amano ◽  
Shigetoshi Sota ◽  
Masaki Nishikawa ◽  
Masato Yoshida ◽  
Makoto Kawaguchi ◽  
...  

ABSTRACTAlGaN/GalnN double heterostructures (DH) were fabricated by metalorganic vapor phase epitaxy on the (0001)Si 6H-SiC substrate. A cleaved edge shows a very flat surface with roughness on the order of one monolayer. Stimulated emission and laser action from the UV to blue region was observed by optical pumping at room temperature (RT). The threshold power density was 27KW/cm2 which is smaller than that of the same structure grown on a sapphire (0001) substrate by a factor of four. A AlGaN/GalnN DH UV light emitting diode, using undoped GalnN is fabricated. The power efficiency and spectra width of this LED is comparable or superior to that of an LED having the same structure but grown on sapphire.


2000 ◽  
Vol 639 ◽  
Author(s):  
Seikoh Yoshida ◽  
Yoshiteru Itoh ◽  
Junjiroh Kikawa

ABSTRACTThe growth of GaNP using laser-assisted metalorganic chemical vapor deposition (LA-MOCVD) was carried out for the fabrication of a light-emitting diode (LED). We used an Ar-F laser in order to decompose the source gases at lower temperatures. Trimethylgallium (TMG), ammonia (NH3) and tertialybuthylphosphine (TBP) were used for the growth. GaNP growth was carried out at different temperatures. After that, annealing was carried out at 1273-1373 K to improve the crystal quality.As a result, N-rich GaNP could be grown at 1123-1223 K. The surface morphologies of GaNP were improved when the growth temperature was increased to above 1173 K. We investigated the photoluminescence (PL) of GaNP. The band-edge emission of GaNP was observed at 77 K upon applying thermal annealing at 1323 K. This peak shifted to about 0.2 eV compared with the GaN band-edge emission. Furthermore, a GaNP LED was fabricated and the electoluminescence spectra were investigated. The band-edge emission at 420 nm was observed.


1995 ◽  
Vol 395 ◽  
Author(s):  
D.A.S. Loeber ◽  
J.M. Redwing ◽  
N.G. Anderson ◽  
M.A. Tischler

ABSTRACTEdge emission characteristics of optically pumped GaN-AlGaN double heterostructures and quantum wells are examined. The samples, which were grown by metalorganic vapor phase epitaxy, are photoexcited with light from a pulsed nitrogen laser. The pump light is focused to a narrow stripe on the sample surface, oriented perpendicular to a cleaved edge, and the edge luminescence is collected and analyzed. We first compare emission characteristics of highly excited GaN-AlGaN double heterostructures grown simultaneously on SiC and sapphire substrates. Polarization resolved spectral properties of edge luminescence from both structures is studied as a function of pump intensity and excitation stripe length. Characteristics indicative of stimulated emission are observed, particularly in the sample grown on SiC. We then present results demonstrating laser emission from a GaN-AlGaN separate-confinement quantum-well heterostructure. At high pump intensities, band edge emission from the quantum well exhibits five narrow (∼1 Å) modes which are evenly spaced by 10Å to within the resolution of the spectrometer. This represents the first demonstration of laser action in a GaN-based quantum-well structure.


2008 ◽  
Vol 45 (4) ◽  
pp. 25-32 ◽  
Author(s):  
L. Dimitrocenko ◽  
J. Grube ◽  
P. Kulis ◽  
G. Marcins ◽  
B. Polyakov ◽  
...  

AlGaN-InGaN-GaN Near Ultraviolet Light Emitting DiodeA 382-nm InGaN/AlGaN light-emitting diode (LED) was made on a sapphire substrate by metal-organic vapour phase deposition (MOCVD) technique. Growing of the undoped and Si-doped GaN and AlxGa1-xN monocrystalline layers with a surface roughness of < 1 nm required for making light emitting devices has been carried out. To enhance the LED emission efficiency, a modified symmetric composition of an active single quantum well (SQW) structure was proposed. In addition to the conventional p-doped AlGaN:Mg electron overflow blocking barrier, ann-doped AlGaN:Si SQW barrier layer in the structure was formed that was meant to act as an additional electron tunneling barrier.


2022 ◽  
Author(s):  
Chen Chen ◽  
Lei Nie ◽  
Yizhe Huang ◽  
Shuang Xi ◽  
Xingyue Liu ◽  
...  

Abstract Herein, we develop a novel strategy for preparing all-inorganic cesium lead halide (CsPbX3, X= Cl, Br, I) perovskite nanocrystals (NCs)@Zn-based metal-organic framework (MOF) composites through interfacial synthesis. The successful embedding of fluorescent perovskite NCs in Zn-MOFs is due to the in-situ confined growth, which is attributed to the re-nucleation of water-triggered phase transformation from Cs4PbBr6 to CsPbBr3. The controllable synthesis of mixed-halide based composites with various emission wavelength can be achieved by adding the desired amount of halide (Cl or I) salts in the re-nucleation process. More importantly, the anion exchange reaction is inhibited among various composites with different halogen atoms by being trapped in MOFs. Besides, a white light-emitting diode (WLED) is produced using a blue LED chip with the green-emitting and red-emitting composites, which has a color coordinate of (0.3291, 0.3272) and a wide color gamut. This work provides a novel route to achieving perovskite NCs growth in MOFs, which also can be extended to the other NCs embedded in frames as well.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1763 ◽  
Author(s):  
Watcharaporn Hoisang ◽  
Taro Uematsu ◽  
Takahisa Yamamoto ◽  
Tsukasa Torimoto ◽  
Susumu Kuwabata

Highly luminescent silver indium sulfide (AgInS2) nanoparticles were synthesized by dropwise injection of a sulfur precursor solution into a cationic metal precursor solution. The two-step reaction including the formation of silver sulfide (Ag2S) nanoparticles as an intermediate and their conversion to AgInS2 nanoparticles, occurred during the dropwise injection. The crystal structure of the AgInS2 nanoparticles differed according to the temperature of the metal precursor solution. Specifically, the tetragonal crystal phase was obtained at 140 °C, and the orthorhombic crystal phase was obtained at 180 °C. Furthermore, when the AgInS2 nanoparticles were coated with a gallium sulfide (GaSx) shell, the nanoparticles with both crystal phases emitted a spectrally narrow luminescence, which originated from the band-edge transition of AgInS2. Tetragonal AgInS2 exhibited narrower band-edge emission (full width at half maximum, FWHM = 32.2 nm) and higher photoluminescence (PL) quantum yield (QY) (49.2%) than those of the orthorhombic AgInS2 nanoparticles (FWHM = 37.8 nm, QY = 33.3%). Additional surface passivation by alkylphosphine resulted in higher PL QY (72.3%) with a narrow spectral shape.


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