四层结构模型下的InAs/GaSb超晶格材料能带计算

Band structure calculation of InAs/GaSb superlattice under 4 layers model

在包络函数近似下采用K.P理论计算了InAs/Ga(In)Sb Ⅱ类超晶格材料的能带结构.同时,计算了超晶格材料的电子有效质量和空穴有效质量,以及不同的结构对应的吸收系数.在此基础上使用了考虑包括界面在内的四层超晶格模型进行能带计算,并与实验结果进行比较,超晶格材料响应截止波长的结果更为接近实验值.不同的界面也会引起能带结构的变化,带来截止波长的变化.对于应变补偿的InAs/GaSb超晶格材料,非对称InSb界面相比对称界面有更大的截止波长.

The band structure of InAs/GaSb superlattice was calculated using K. P theory under the envelope-function ap- proach. The electro effective mass and absorption coefficient with different material structure were also calculated. Four- layer structure model considering two interfaces was investigated and used to modify the calculation. Comparing with the experiment results, this four layer model has closer cutoff wavelength than standard model. The results showed that dif- ferent interface structure can also influence the band structure, leading to the changes of cutoff wavelength. For the same InAs/GaSb superlattice material fully compensated with InSb interface, one with symmetric InSb interfaces has shorter cutoff wavelength than supedattice with asymmetric interfaces.