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文章研究了短周期InAs/GaSb(SLs)Ⅱ型超晶格的红外光电特性。研究发现将InAs/GaSb超晶格各层生长宽度调节在20/25左右,可以实现中红外波段的禁带宽度。我们发展了修正的八能带K.P模型计算了该超晶格系统的电子子带结构,模型充分考虑了生长层之间的界面效应。模型只需要微观界面效应这一个可调参数,就可以得到与实验结果符合的非常好的理论结果。研究发现将GaSb的厚度固定为24,InAs的厚度从23降到17时,SLs的带隙宽度可以从275 meV调节到346 meV;或者InAs的厚度为21,GaSb的厚度从18增加到27时,SLs的带隙宽度可以从254meV调至313meV。该理论研究证明短周期InAs/GaSbⅡ型SLs可以应用于带宽为3~5μm的中红外光电探测。
The article investigates the infrared photoelectric properties of short-period InAs / GaSb (SLs) type II superlattices. The study found that the InAs / GaSb superlattice layer growth width adjustment of 20/25 or so, you can achieve the band gap in the mid-infrared band. We developed a modified octave band K.P model to calculate the electronic sub-band structure of the superlattice system. The model fully considers the interfacial effect between the growth layers. The model only needs an adjustable parameter of the micro-interface effect, so that very good theoretical results that accord with the experimental results can be obtained. The results show that when the thickness of GaSb is fixed at 24 and the thickness of InAs is reduced from 23 to 17, the bandgap width of SLs can be adjusted from 275 to 346 meV. Alternatively, the thickness of InAs is 21 and the thickness of GaSb is 18Å When is increased to 27, the bandgap width of SLs can be adjusted from 254meV to 313meV. The theoretical study shows that the short-period InAs / GaSb II SLs can be applied to mid-infrared photodetection with bandwidth of 3 ~ 5μm.