Research On Optimization Of Luminescent Properties Of InGaAsSb/AlGaAsSb Quantum Well Laser Materials

Semiconductor lasers are widely used in many fields,such as atmospheric monitoring,laser ranging,space communication,laser surgery and laser cosmetology,because of small size,adjustable wavelength and high reliability.Semiconductor lasers which luminescence band is 2 ?m are working in the field of national defense,for example lidar,laser guidance and aerospace,and the future development and application prospects of them have attracted a lot of attention of people.For semiconductor lasers which luminescence band is 2 ?m,the best choice is antimonide alloy.However,in the epitaxial grown of antimonide alloy materials,there will inevitably be introduced defects and molecular clusters,which will seriously affect the crystal quality of the materials.The results lead to the localized luminescence of the material and the luminescent property is decreased.Compared with Ga Sb substrate,Ga As substrate has the advantages of low cost and simple preparation process.Combined with many advantages of Ga As substrate,in this paper,we grow the InGaAsSb/AlGaAsSb quantum well laser materials by using molecular beam epitaxy.In order to improve the luminescent properties of InGaAsSb/AlGaAsSb quantum well laser materials,we use rapid thermal annealing to treat the quantum well materials.Using photoluminescence spectroscopy and X-ray diffraction,we systematically discuss the effects of luminescent properties and structure of quantum well materials when the materials are treated by rapid thermal annealing.The main research contents of this study are as follows:(1)In order to realize the InGaAsSb/AlGaAsSb quantum well laser materials emitting about 2 ?m wavelength,we design a quantum well structure.We use molecular beam epitaxy to grow the basic thin film materials of the quantum well structure,including Ga Sb,InGaAsSb and AlGaAsSb alloy films.The X-ray diffraction is used to characterize the films.The results are proved that the semiconductor thin films have high crystal quality which are grown by molecular beam epitaxy.(2)We use molecular beam epitaxy to grow the InGaAsSb/AlGaAsSb quantum well laser materials and study the luminescent properties of them.We analyse that the quantum well samples have good luminescent properties and crystal quality by X-ray diffraction and photoluminescence spectroscopy.At room temperature,the luminescent wavelength is 1.96 ?m of InGaAsSb/AlGaAsSb quantum well materials.We also determine the luminescence source of the quantum well samples.The light emission of photon energy of 0.687 e V comes from the local carrier recombination,and the light emission of 0.701 ev comes from the free exciton recombination.(3)In order to improve the luminescent properties of InGaAsSb/AlGaAsSb quantum well laser materials,this paper studies the quantum well materials are treated by rapid thermal annealing.The results of X-ray diffraction show that the atoms in the quantum well materials can interdiffusion at the interface between the well layer and the barrier layer by rapid thermal annealing.This kind of interdiffusion can improve the crystal quality of quantum well materials,reduce the structural strain,and improve the luminescent properties of quantum well materials.When the annealing temperature increases,it is found that the peak of room temperature photoluminescence will shift to short wavelength.In addition,the recombination ratio of local carriers in the samples can reduce when the annealing temperature is increasing.Compared with the luminescence intensity of local carriers and free excitons when the annealing temperature is 500 ? and600 ?,we found that the latter is only 22.6 % of the former.In this paper,we study the antimonide semiconductor laser materials which are grown by molecular beam epitaxy,and improve the luminescent properties of the materials.It lays a foundation for the preparation of high performance antimonide semiconductor lasers.