【摘要：InGaAs/GaAsSb的超晶格结构对于光检测器和发光器件非常重要。然而，高品质的GaAsSb合金的生长是一个挑战。最近，来自中国科学院的一个研究小组已经成功地获得了高品质的InGaAs/GaAsSb超晶格结构，发表在《中国科学: 物理学 力学 天文学》2015年58卷第4期。

Summary：InGaAs/GaAsSb superlattice (SL) structure is very attractive in photodetectors (PD) and light emitting devices. However, the growth of high quality GaAsSb alloys is a challenge. In 2015 (4) issue of Science China, a research team from CAS has successfully obtained high quality InGaAs/GaAsSb Superlattice structures based on the comprehensive study of growth mechanism.】

The high crystalline quality of GaAsSb and InGaAs is desired for application in opo-electronic. Professor Jianxin Chen and his group from Chinese Academy of Sciences set out to tackle this program.After years of researches, they have comprehensive studied the growth mechanism and successfully obtained high quality InGaAs/GaAsSb Superlattice structures. Their work, entitled “Growth mechanism and optical properties of InGaAs/GaAsSb Superlattice structures”, was published in SCIENCE CHINA, 2015, Vol (4).

The high quality of GaAsSb alloys is the key factor of the high quality InGaAs/GaAsSb SL material. The effects of different factors on the growth GaAsSb alloys was studied. And the incorporation behavior of Sb and As in GaAsSb was explained by the non-equilibrium thermodynamic model.As shown in Figure 1, the calculated results (solid line) are in good agreement with the experimental data (solid circles). The non-equilibrium thermodynamic model can well describe the MBE growth process and the incorporation rule of As and Sb in the GaAsSb material.

Figure 1  Antimony composition as a function of Sb and As beam equivalent pressure ratio .

By optimizing the growth parameter, high quality InGaAs/GaAsSb superlattice was obtained. A slight blue-shift of PL peak energy in InGaAs/GaAsSb superlattice photoluminescence (PL) spectrum was observed, which is attributed to the band bending effect of photo-excited carriers. the temperature dependence of the PL peak energy and the integrated intensity were also analyzed by the group. The results are shown in the Figure 2 and 3.

Figure 2  Dependence of PL peak energy of the SL on the cubic root of excitation power.

Figure 3  Dependence of PL peak energy of the SL on temperature.

This research project was partially supported by the National Natural Science Foundation of China and the National Basic Research Program of China.

See the article:Jin C, Xu Q Q, Chen J X. Growth Mechanism and Optical Properties of InGaAs/GaAsSb Superlattice Structures. Sci China-Phys Mech Astron 2015, 58(4): 044202

http://phys.scichina.com:8083/sciGe/EN/abstract/abstract509419.shtml

http://link.springer.com/article/10.1007/s11433-014-5601-3

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