利用分子束外延生长获得的两个InAs量子点样品制备了n型的量子点红外探测器.对于其中一个器件,在InAs量子点有源区的底部和顶部分别插入生长了AlGaAs势垒层.利用透射电阻显微技术研究了两个样品的结构特性;利用光致发光光谱和光电流谱研究了两个器件的光电性质.实验结果表明,AlGaAs层的插入对器件的探测性质有显著的影响.利用有三维效质量近似模型的计算结果,指认了带内光电流谱中峰结构的起源.
Two InAs quantum dot samples have been grown by the solid source molecular beam epitaxy (MBE) and fabricated to detectors. AlGaAs thin films have been inserted into the source region for one of the two devices. The structural features of the two samples have been studied by using the transmission electron microscope (TEM). The photoelectric properties of them have been measured by the photoluminescence (PL) and photocurrent (PC) spectra. The experimental results indicated that the AlGaAs films have profound effects on the properties of the detector. According to the calculations based on effective mass approximation, the origins of the photocurrent peaks of the two devices have been identified.