Abstract
The main intention of this thesis is growth and characterization of InAs/GaAs quantum dot (QD) heterostructure with 1.3 μm emission wavelength and fabricates 1.3 μm-emitting InAs/GaAs quantum dot resonant cavity light-emitting diode (QD RCLED). The QD heterostructure have been successfully realized via Stranski-krastanow growth mode, and the structural and the optical characteristics of InAs QDs determinate by growth parameters. Firstly, we investigate the growth-temperature and growth-rate effect of InAs QDs on GaAs substrate grown by low pressure metalorganic chemical vapor deposition (LP MOCVD). The lower growth temperature makes for the formation of InAs QDs with different growth temperatures, and the optimum optical characteristic of InAs QDs is grown at 500℃, which can extend the emission wavelength to 1.3 μm with strongest photoluminescence (PL) intensity, the narrowest full width at half maximum of 30.8 meV as compare to grow at other growth temperatures. In various growth rates tuning experiment, lower growth rate forms more irregular relaxed islands, and the weaker PL peak intensity is shown in the PL spectrum. Secondly, InAs QD resonant cavity light-emitting diode with 1.32 μm-emitting has been successfully fabricated at room temperature in our work. The active medium of QD RCLED was a single-sheet 3.0 ML InAs QDs inserted in GaAs matrix grown by metalorganic chemical vapor deposition. The epitaxial AlGaAs/GaAs pairs and one dielectric SiO2/Si3N4 pair as distributed Bragg reflectors (DBRs) are fabricated as the bottom and top mirrors of QD RCLEDs, which can provide high cavity factor and avoid the In/Ga intermixing of InAs QD during fabricating the top mirror. The InAs/GaAs QD RCLEDs present an emission wavelength of 1.318 mm, a narrow full width at half maximum in the electroluminescent spectrum of 14 meV at 20 mA, a high Q factor of 73.9, a low redshift rate with injection current of 0.033 nm/mA, and a light-output power of 28 mW at 100 mA. Finally, we investigate the structural and the optical characteristics of InAs QDs grown on InGaAs strained buffer layer (SBL). The InAs QD density can increase to 3.5 x 1010 cm-2 as InAs QD deposited on InGaAs SBL, and the QD size uniformity is better than InAs QD directly deposited on GaAs layer. Under highest excited density at low temperature, PL spetra shows the ground, first and second states of InAs QDs due to the state-filling effect; the temperature-dependent PL shows the PL peak energy has a redshift following the Varshni relation and an unusual temperature dependence of linewidth which first reduces and then increases with increasing temperature for the InAs QDs on the InGaAs SBL. The PL thermal quenching arises from the carrier escape of the dots to nonradiative recombination centers like defects. The single sheet InAs QD/ InGaAs SBL edge-emitting p-i-n LEDs is emitting at 1330 nm with an external quantum efficiency of 0.024% at room temperature.