Study On The Epitaxy Of 3-5?m Medium Infrared Semiconductor Laser Materials

The mid-infrared 3-5?m band is an important window of the atmosphere,and antimony semiconductors laser material are the ideal material system for the research of optoelectronic materials and devices in this infrared band.GaSb based quantum well lasers have been the preferred materials for mid-infrared detectors and lasers due to their high photoelectric conversion efficiency and good material stability.It has been widely used in air pollution monitoring,sensing technology,infrared imaging,remote sensing,surgical medicine,free space communications,optoelectronic countermeasures,laser radar and other civilian / military applications.In this paper,GaSb based quantum well materials are studied by molecular beam epitaxy.The epitaxial growth,interfacial strain and luminescence properties of GaSb based "W" type quantum wells lasers is investigated.In this thesis,the epitaxy of 3-5 ?m medium infrared semiconductor lasers is studied.The main contents of the study are as follows:(1)A theoretical model of "W" type laser band structure was constructed,and the arrangement of the band gaps in the type II band gaps of the InAs,GaSb,AlSb,and GaInSb materials systems is clarified,and the effects of material composition,thickness,and cascade structure on wave function are analyzed.At the same time,optimize the design of the buffer layer,the waveguide layer,the symmetric equivalent confinement layer and other structures.(2)MBE epitaxial growth of the design structure,through the beam flow,growth temperature,V / III beam ratio,growth rate and other growth parameters to optimize the precise control of III,V group material composition,thickness and strain.In situ monitoring with RHEED was used to control the growth process of epitaxial materials,and high-quality material interface was obtained.At the same time,the structure and luminescence characteristics of different in components in GaInSb ternary alloys were systematically studied to meet the design requirements.(3)The cascade region of "W" type quantum well in the whole structure of the designed "W" type quantum well laser is grown by epitaxial growth,and its physical properties are studied.On this basis,the epitaxial growth of the full structure material of "W" type quantum well laser is studied.The EL luminescence is about 3.76 ?m,which meets the designed target wavelength.In order to adjust the structure in the range of 3-5 ?m,we increase the thickness of InAs from 4 atomic layers to 5 atomic layers,and increase the luminescence spectrum from 3.63 ?m to 4.07 ?m.A "W"-type quantum well material with an adjustable lightemitting wavelength of 3 to 5 ?m is realized,which lays a foundation for the preparation of the middle infrared semiconductor laser.