The Research For Growth And Structure Of GaAs-based InAs/GaSb Superlattices

Because of the low absorption coefficient and scattering rate in the atmosphere,light of 2~5μm band has important application prospect in laser radar,space point-to-point communication and military target indication.Antimonide semiconductor lasers are one of the most commonly used methods for obtaining laser in this wavelength range.However,defects such as lattice mismatch and stress in the process of preparing antimonide materials seriously degrade their luminescent properties and hinder their development and application.Therefore,in this dissertation,the crystal quality and internal stress of heteroepitaxial growth monolayers(GaSb thin films grown on GaAs substrates)and heteroepitaxial growth superlattices(InAs/GaSb superlattices grown on GaAs substrates)Control the mismatch between intermetallic interfaces in the superlattice cycle and improve superlattice performance.GaSb thin films were grown on GaAs substrates by molecular beam epitaxy.The crystal quality of thin films was measured by twin crystal XRD.Sharp diffraction peaks were observed.The experimental results are compared with the images obtained by epitaxial growth of X’ Pert Epitaxy simulation software.It is found that the experimental results are consistent with the theoretical simulation,indicating that the lattice quality of the epitaxial thin films is good and the optimal growth parameters are determined.The InAs/GaSb superlattices with periodic thicknesses of(17ML/17ML),(28ML/17ML)and(17ML/14ML)were grown by using the best growth parameters.The half-width of the first-Respectively 0.194°,0.104°,0.207°.The results show that the crystal quality of the superlattice increases with the increase of the thickness of InAs layer in a certain period of time,and the increase of the GaSb layer thickness also improves the crystal quality of the superlattice.In general,with the same growth period,the superlattices with larger periodic thicknesses have less stress and the better the crystal quality of InAs/GaSb superlattices.