Infrared multispectral photodetectors with high performance show great potential in a broad range of applications. Here, sensitive and controllable dual-color photodetection at $10.6$ and $15.7\hspace{0.17em}\mu \mathrm{m}$ is demonstrated by using a charge sensitive infrared phototransistor (CSIP) with dynamical optical gate. The CSIP device is fabricated in a GaAs/AlGaAs double quantum well (QW) crystal with both upper and lower QWs (7 and 11 nm thick, respectively) being photosensitive via intersubband absorption and, hence, each QW corresponding to one target wavelength ($10.6$ and $15.7\hspace{0.17em}\mu \mathrm{m}$, respectively). Moreover, the upper QW serves as a photosensitive floating gate (FG), while the lower QW functions as the conducting channel of the phototransistor. By periodically lifting-up (lowering-down) the electrostatic potential of FG, the photoresponse at $10.6$ ($15.7\hspace{0.17em}\mu \mathrm{m}$) associated with photoexcitation in upper (lower) QW can be achieved. This electrically controllable photoresponse together with intrinsically high photoconductive gain (∼10²) provides a scheme to realize sensitive dual-color photodetection for infrared optoelectronic applications.

中文翻译：

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具有动态光闸的双色电荷敏感红外光电晶体管

具有高性能的红外多光谱光电探测器在广泛的应用中显示出巨大的潜力。在这里，灵敏且可控的双色光电探测在$10.6$ 和 $15.7\hspace{0.17em}\mu \mathrm{米}$通过使用具有动态光门的电荷敏感红外光电晶体管 (CSIP) 来证明。CSIP 器件是在 GaAs/AlGaAs 双量子阱 (QW) 晶体中制造的，上下 QW（分别为 7 和 11 nm 厚）通过子带间吸收具有光敏性，因此每个 QW 对应一个目标波长（$10.6$ 和 $15.7\hspace{0.17em}\mu \mathrm{米}$， 分别）。此外，上部 QW 用作光敏浮动栅极 (FG)，而下部 QW 用作光电晶体管的导电沟道。通过定期升高（降低）FG 的静电势，在$10.6$ ($15.7\hspace{0.17em}\mu \mathrm{米}$) 与上（下）QW 中的光激发相关联。这种电可控的光响应连同固有的高光电导增益（~10 ²）提供了一种实现红外光电应用的灵敏双色光电检测的方案。