【摘要】 与量子阱红外探测器相比,量子点红外探测器具有不制作表面光栅就能在垂直入射红外光照射下工作以及工作温度更高等优势。然而,目前阻碍量子点红外探测器性能提高的技术瓶颈主要来自组装量子点较差的大小均匀性、较低的量子点密度以及垂直入射下子带跃迁吸收效率低等原因。利用分子束外延技术研究了如何从量子点材料生长和器件设计两方面来克服这些困难,并且制作了几种不同结构的InGaAs/GaAs量子点红外探测器。在77 K时,这些器件在垂直入射条件下观察到了很强的光电流信号。更多还原

【Abstract】 Quantum dot infrared photodetector(QDIP) exhibits some advantages such as operation under the normal incidence infrared irradiation without fabricating the surface gratings and higher working temperature compared with quantum well infrared photodetector.However,the present technical bottlenecks to enhance the QDIP device performance are large size fluctuation of the self-assembled QDs,low dot density and low intersubband absorption efficiency under the normal incidence irradiation.This work investigates that how to overcome these difficulties in terms of the QD material growth and the device design,and several types of InGaAs/GaAs QDIP devices are fabricated by using molecular beam epitaxy.Strong photocurrent signals are observed for the QDIPs under the normal incidence condition at the temperature of 77 K.更多还原