MQWSMultiple Quantum Well Structures
Copyright 1988-2018, All rights reserved.
References in periodicals archive ?
In this paper, we investigated the optimized growth conditions, laser structures design, and doping characters of InGaAsSb/AlGaAsSb MQW lasers, which were grown with superlattice layer, and GaSb-based type I diode lasers with up to 2.3 [micro]m wavelength was fabricated and characterized, indicating excellent lattice matching and thus high crystalline quality.
Figure 5 shows the SEM and mono-CL images of the LEDs recorded at the wavelengths corresponding to the peak emissions of the GaN, high-energy, and blue emissions from the InGaN/GaN MQWs. Although the V-pit defects on the surface of the sample are not able to be seen in the SEM image [Figure 5(a)], dislocations inside the LED structure can be observed in the CL images as in Figures 5(b)-5(d).
In the localized exciton model, trap centers are originated from a spatial disorder such as the fluctuation of indium within InGaN/GaN MQWs. Using TMIn treatment, the decay time becomes shorter, because treatment leads to more strongly localized stats due to the indium cluster [18].
The InGaN/GaN MQWs green LED structure (as shown in Figure 1) was grown on silicon (111) substrate by Thomas Swan 6 x 2" MOCVD with close-coupled showerhead reactor.
Microwave SiGe/Se photodiodes, integrated with SiGe/Si channel waveguides, have been demonstrated in SiGe/Si metal-semiconductor-metal (MSM) Schottky diodes and in SiGe/Si multiple quantum well (MQW) avalanche and PIN diodes.[15]
However, in conventional planar epilayers, the InGaN/GaN multiple quantum well (MQW) contains large strain, which would induce a high dislocation density and piezoelectric field, due to the mismatches in lattice constant and thermal expansion between heteroepitaxial layers.
In Figure 6(a), it shows that most of the light generated in the MQWs active layer is trapped inside the device due to the refractive index difference between the semiconductor and the surrounding medium.
The five periods InGaN/GaN multiple quantum well (MQW) with emission wavelength in the blue region, a 50 nm thick Mg-doped p-AlGaN electron blocking layer, and a 0.2 [micro]m thick Mg-doped p-GaN cladding layer were grown at 1050[degrees]C.
After growing the samples, postannealing was needed to activate the top p-GaN layer of InGaN/GaN MQWs LED at 700[degrees]C and 20 min.
Photons generated in the multiple quantum well (MQW) regions may escape more efficiently at the ITO/air sidewall interfaces through the circular hole patterns due to the unfolded side surface areas.
In this study, we present a detailed study of a Ge/ [Si.sub.0.16][Ge.sub.0.84] MQW structure grown on Ge-on-Si VS by temperature-dependent PR measurements in the range between 10 and 300 K.