使用分子束外延生长设备, 在GaAs (100)衬底上生长了量子阱宽度为3 nm的GaAs/AlAs多量子阱样品, 并在量子阱层中央进行了Be受主的δ-掺杂。根据量子限制受主从束缚态到非束缚态之间的跃迁, 设计并制备了δ-掺杂Be受主GaAs/AlAs多量子阱太赫兹光探测器原型器件。在4.2 K温度下, 分别对器件进行了太赫兹光电流谱和暗电流-电压曲线的测量。在6 V直流偏压下, 空穴载流子沿量子阱层方向输运。当正入射激光频率为6.8 THz时, 器件响应率为2×10-4 V/W(2 μA/W)。通过器件的暗电流-电压曲线计算了器件全散粒噪声电流,在4.2 K、6 V直流偏压下, 全散粒噪声电流为5.03 fA·Hz-1/2。

3 nm well-width GaAs/AlAs multiple-quantum wells were grown by molecular beam epitaxy with Be acceptors δ-doped at quantum-well center on a semi-insulating GaAs (100) substrate. According to the transitions from bound to unbound states of quantum-confined acceptors, the terahertz prototype photodetector based Be acceptors-doped GaAs/AlAs multiple-quantum wells was designed and fabricated. The terahertz photocurrent spectrum and dark current-voltage characteristics of the device were measured at 4.2 K, respectively. Under a bias of 6 V and the normal incidence of a 6.8 THz laser, the hole carriers transport along quantum well layers, and the photodetector responsivity is 2×10-4 V/W (2 μA/W). According to the I-V curves measured at 4.2 K, the device full-shot noise current was calculated. It is 5.03 fA·Hz-1/2 with a bias of 6 V.