InAs/AlSb/GaSb量子阱中的双色光吸收

为了降低噪声对InAs/GaSb量子阱作为双色电探测器性能的影响,设计性能优良的光电探测器,在InAs/GaSb量子阱中加入AlSb夹层,以减少电子和空穴在界面处的复合,从而抑制由于电子和空穴复合引起的噪声。首先应用转移矩阵方法求解薛定谔方程得到量子阱中电子和空穴的能级和波函数,研究AlSb夹层对电子和空穴波函数的影响。应用平衡方程方法求解外加光场条件下的玻尔兹曼方程,研究所有电子和空穴跃迁通道对光吸收系数的贡献,重点研究了AlSb夹层厚度对光吸收系数的影响。结果表明:基于In As/GaSb的量子阱体系可以实现双色光吸收,加入AlSb夹层可以有效抑制电子和空穴在界面处的隧穿,从而降低复合噪声,同时AlSb夹层的加入也对吸收峰有影响。AlSb夹层的厚度达到2 nm即可有效降低电子和空穴复合噪声,双色光吸收峰在中远红外波段,为该量子阱作为性能良好的中远红外光电探测器提供理论支撑。

Two Color Optical Absorption in InAs/AlSb/GaSb Quantum Well System

In order to suppress the noise and improve the performance of the detector, AlSb caplayer was inserted between InAs layer and GaSb layer. The transfer matrix method was employed to solve the SchrÖdinger equation to get the wavefunctions and subband energies for electron and hole. The optical absorption coefficients were obtained by solving the Boltzmann equation with the balance equation method. The effects of AlSb caplayer on the intersubband optical transition were investigated in detail. The noise induced by the electron-hole combination can be suppressed efficiently when the width of AlSb caplayer reaches up to 1 nm. Two peaks of the optical absorption are observed at the mid-and-far infrared bandwidth indicating that InAs/AlSb/GaSb based type Ⅱquantum well system can be used as mid-and-far infrared photoelectric detector.