Room-Temperature CW Operation of SQW Lasers on Si Grown with AiGaAs/AlGaP Intermediate Layers by MoCVD

1991 ◽  
Vol 228 ◽  
Author(s):  
T. Egawa ◽  
Y. Hayashi ◽  
T. George ◽  
T. Soga ◽  
T. Jimbo ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Si Substrate ◽  
Si Substrates ◽  
Grown Sample ◽  
Cw Operation ◽  
Intermediate Layers ◽  
Dimensional Growth

ABSTRACTThe heterointerfaces of single quantum wells (SQWs) and the characteristics of SQW lasers on Si substrates grown with Al0.5 Ga0 5As/Al0.55Ga0.45P intermediate layers (AlGaAs/AlGaP ILs) entirely by MOCVD are reported. The surface morphology and the heterointerfaces of SQWs grown on Si substrates with the AlGaAs/AlGaP ILs are smoother than those of the two-step-grown sample. The two-dimensional growth of the AlGaAs/AlGaP ILs on a Si substrate contributes to obtain the smooth heterointerface. The excellent lasing characteristics are obtained by the AlGaAs/AlGaP ILs, which are caused by the smooth heterointerfaces. The lasers grown with the AlGaAs/AlGaP ILs show the averaged threshold current density of 1.83 kA/cm2 and the averaged differential quantum efficiency of 51.9 % under cw condition at room temperature.

Room-Temperature CW Operation of AlGaAs/GaAs SQW Lasers on Si Substrates by MOCVD Using AlGaAs/AlGaP Intermediate Layers

1990 ◽  
Vol 29 (Part 2, No. 7) ◽  
pp. L1133-L1135 ◽  
Author(s):  
Takashi Egawa ◽  
Yasufumi Kobayashi ◽  
Yasuhiko Hayashi ◽  
Tetsuo Soga ◽  
Takashi Jimbo ◽  
...  
Keyword(s):  
Room Temperature ◽  
Si Substrates ◽  
Cw Operation ◽  
Intermediate Layers

Luminescence from Germanium and Germanium on Silicon

2013 ◽  
Vol 205-206 ◽  
pp. 383-393 ◽  
Author(s):  
Tzanimir Arguirov ◽  
Martin Kittler ◽  
Michael Oehme ◽  
Nikolay V. Abrosimov ◽  
Oleg F. Vyvenko ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Excitation Level ◽  
The Other ◽  
Photoluminescence Spectra ◽  
Si Substrates ◽  
Similar Dependence ◽  
Direct Band

We present an overview on generation of direct gap photo- and electroluminescence in Ge bulk wafers, Ge thin films deposited on Si, and Ge p-i-n diodes prepared on Si substrates. We analyzed the emission in a spectral range from 0.45 eV to 0.95 eV, covering the radiation caused by direct gap transitions, the indirect one, and also the luminescence related to transition on dislocations. The temperature and excitation level strongly influence the intensities of direct and indirect photoluminescence in bulk samples. As it could be expected, high temperature and excitation favour the generation of direct gap luminescence. Intrinsic bulk Ge shows a quadratic dependence of the direct gap luminescence on the excitation and a sub-quadratic one for the indirect. The photoluminescence spectra taken from intrinsic Ge on Si layers show features related to dislocations. There are two spectral regions associated with dislocation recombination. At room temperature one is at around 0.45 eV and the other at 0.72 eV. We found strong direct gap radiation from the Ge p-i-n diodes with intrinsic, highly dislocated active area (dislocation density of about 108-1010 cm-2). There is a threshold current density of 8 kA/cm2, at which the direct band luminescence becomes a super-quadratic. The dependence of the radiation intensity on the excitation is governed by a power law with exponent of 1.7 before reaching that threshold and 4.5 after exceeding it. Above the threshold the dislocation radiation shows similar dependence on the excitation as the direct band luminescence.

Characteristics of Mocvd-Grown AlGaAs/GaAs Sqw Lasers and GaAs Mesfetsfabrication on Si Substrate with SiO2-Back Coating

1990 ◽  
Vol 198 ◽  
Author(s):  
Takashi Egawa ◽  
Hitoshi Tada ◽  
Yasufumi Kobayashi ◽  
Shinji Nozaki ◽  
Tetsuo Soga ◽  
...  
Keyword(s):  
Electron Concentration ◽  
Thermal Cycle ◽  
Room Temperature ◽  
Threshold Current ◽  
Gaas Layer ◽  
Si Substrate ◽  
Thermal Cycle Annealing ◽  
Cw Operation ◽  
Lower Background ◽  
Undoped Gaas

ABSTRACTWe discuss room temperature CW operation of AlGaAs/GaAs SQW lasers and GaAs MESFETs with good pinch-off characteristic on SiO2 -back coated Si. The all-MOCVD-grown,SQW laser on Si with thermal-cycle annealing, which has the EPD of 1.5 × 107 cm−2, has the threshold current as low as 55 mA (1.41 kA/cm2) under CW operation at room temperature. The pinch-off and the sidegating effect characteristics of GaAs MESFETs on Si have been improved by using SiO2-back coating of Si and higher growth temperature. The maximum transconductance of 160 mS/mm has been obtained for the MESFET with a 2.5 × 15 µm gate. The main origin of sidegating effect associates with the channel layer-undoped GaAs layer beneath it interface. The SiO2 -back coating is found effective to obtain a lower background electron concentration in undoped GaAs layer and to control doping of the active layer in GaAs/Si.

InAs Quantum Dots in AlAs/GaAs Short Period Superlattices: Structure, Optical Characteristics and Laser Diodes

2001 ◽  
Vol 707 ◽  
Author(s):  
Vadim Tokranov ◽  
M. Yakimov ◽  
A. Katsnelson ◽  
K. Dovidenko ◽  
R. Todt ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Inas Quantum Dots ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices ◽  
Emitting Lasers ◽  
Cladding Layers

ABSTRACTThe influence of two monolayer - thick AlAs under- and overlayers on the formation and properties of self-assembled InAs quantum dots (QDs) has been studied using transmission electron microscopy (TEM) and photoluminescence (PL). Single sheets of InAs QDs were grown inside a 2ML/8ML AlAs/GaAs short-period superlattice with various combinations of under- and overlayers. It was found that 2.4ML InAs QDs with GaAs underlayer and 2ML AlAs overlayer exhibited the lowest QD surface density of 4.2x1010 cm-2 and the largest QD lateral size of about 19 nm as compared to the other combinations of cladding layers. This InAs QD ensemble has also shown the highest room temperature PL intensity with a peak at 1210 nm and the narrowest linewidth, 34 meV. Fabricated edge-emitting lasers using triple layers of InAs QDs with AlAs overlayer demonstrated 120 A/cm2 threshold current density and 1230 nm emission wavelength at room temperature. Excited state QD lasers have shown high thermal stability of threshold current up to 130°C.

scholarly journals Room Temperature CW Operation of GaN-based Blue Laser Diodes by GaInN/GaN optical guiding layers

2000 ◽  
Vol 5 (S1) ◽  
pp. 1-7 ◽  
Author(s):  
Masayoshi Koike ◽  
Shiro Yamasaki ◽  
Yuta Tezen ◽  
Seiji Nagai ◽  
Sho Iwayama ◽  
...  
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Laser Diodes ◽  
Threshold Current ◽  
Crystal Defects ◽  
Blue Laser ◽  
Buffer Layers ◽  
Continuous Wave Laser ◽  
Cw Operation ◽  
First Time

GaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm2). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.

1.5 micron InAs quantum dot lasers based on metamorphic InGaAs/GaAs heterostructures.

2003 ◽  
Vol 794 ◽  
Author(s):  
V.M. Ustinov ◽  
A.E. Zhukov ◽  
A.R. Kovsh ◽  
N.A. Maleev ◽  
S.S. Mikhrin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Active Region ◽  
Quantum Wells ◽  
Gaas Substrate ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Optical Loss ◽  
Threshold Current ◽  
Temperature Threshold

ABSTRACT1.5 micron range emission has been realized using the InAs quantum dots embedded into the metamorphic InGaAs layer containing 20% of InAs grown by MBE on a GaAs substrate. Growth regimes were optimized to reduce significantly the density of dislocations propagating into the active layer from the lattice mismatched interface. 2 mm long InGaAs/InGaAlAs lasers with 10 planes of quantum dots in the active region showed threshold current density about 1.4 kA/cm2 with the external differential efficiency as high as 38%. Lasing wavelength depends on the optical loss being in the 1.44–1.49 micron range at room temperature. On increasing the temperature the wavelength reaches 1.515 micron at 85C while the threshold current characteristic temperature of 55–60K was estimated. High internal quantum efficiency (η>60%)and low internal losses (α=3–4 cm ) were realized. Maximum room temperature output power in pulsed regime as high as 5.5 W for 100 micron wide stripe was demonstrated. Using the same concept 1.3 micron InGaAs/InGaAlAs quantum well lasers were fabricated. The active region contained quantum wells with high (∼40%) indium content which was possible due to the intermediate InGaAs strain relaxation layer. 1 mm stripe lasers showed room temperature threshold current densities about 3.3 kA/cm (λ=1.29 micron) and 400 A/cm2 at 85K. Thus, the use of metamorphic InGaAs layers on GaAs substrate is a very promising approach for increasing the emission wavelength of GaAs based lasers.

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