Investigations On Novel GaAs-Based And Si-Based Optoelectronic Material Systems

The frabrication of high-performance GaAs-based and Si-based monolithically integrated optoelectronic devices is an important research direction of integrated optoelectronic technology. And the major outstanding issues, which have been encountered during the investigation of monolithically integrated optoelectronic devices, are the heterogeneous compatibilities between different materials. At the present, there are many ways to solve this issue, and theoretical prediction and experimental synthesis of the novelⅢ-Ⅴintegrated optoelectronic materials lattice-matched to substrates is one of the effective ways. On the other hand, InAs/GaAs self-organized quantum dots grown on GaAs substrates can be used to fabricate 1.3-1.55μm high-performance quantum dot lasers, and it has some significance for improving the performance of optical communication systems.In this thesis, that is mainly focused on the novelⅢ-Ⅴintegrated optoelectronic materials grown on GaAs and Si substrates. Besides, the growth of InAs/GaAs quantum dots has also been carried out. Research results, as listed below:1,Using the non-coated graphite susceptors, a series of BxAl1-xAs samples have been grown on (100)GaAs substrates by low-pressure metal-organic chemical vapor deposition. Compared with the SiC-coated graphite susceptors, optimum growth temperature range of BxAl1-xAs alloys increased from 580℃to 610℃, and boron composition x also increased. At 610℃, assuming total relaxation of BAlAs layers, solid boron composition x increased from 1.2% to 4.7% with the increment of gas phase triethylboron (TEB) mole fraction, and the full-width at half-maximum (FWHM) value of BxAl1-xAs diffraction peak increased. Meanwhile, root mean square (RMS) roughness of the BxAl1-xAs samples measured by AFM also increased.2,BxAl1-x-yInyAs was grown lattice-matched to GaAs substrates successfully. Moreover,10-period BxAl1-xAs/GaAs(x=2.8%) and BxAl1-x-yInyAs/GaAs(x=2.8%) MQW heterostructures were also demonstrated.3,Involved in the LP-MOCVD growth of InAs/GaAs self-organized quantum dots on GaAs substrates. The RT-PL peak wavelength of 4.0ML InAs QDs covered with GaAs layers reached 1194nm, and the full-width at half-maximum (FWHM) value was 39meV.InAs quantum dots were grown at 500℃with growthrate of 0.1ML/s andⅤ/Ⅲratio of 10.4,In order to calculate the band gap of GaInNP, the lattice constants and energy band gap structures of GaN, GaP, InN and InP were calculated by the CASTEP software which is based on density-functional theory (DFT).5,The energy band gap structures of GaNP, GaInP, GaInN and InNP were calculated, and the bowing parameters were obtained by the conic fitting. Moreover, the direct bandgap bowing parameter of GaNP was 6.29eV. Beside, the energy band gap range of GaInNP lattice-matched to Si substrates with different N content were calculated, and when the N composition was 0.13, GaInNP changed from an indirect bandgap material to a direct bandgap one.