GaAs/GaAsSb Core-Shell Configured Nanowire-Based Avalanche Photodiodes up to 1.3?m Light Detection

We report the first study on a GaAs/GaAsSb core-shell (CS)-configured nanowire (NW)-based separate absorption, charge control, and multiplication region avalanche photodiode (APD) operating in the near-infrared (NIR) region. Heterostructure NWs consisted of GaAs and tunable band gap GaAs1-xSbx serving as the multiplication and absorption layers, respectively. A doping compensation of absorber material to boost material absorption, segment-wise annealing to suppress trap-assisted tunneling, and an intrinsic i-type and n-type combination of the hybrid axial core to suppress axial electric field are successfully adopted in this work to realize a room-temperature (RT) avalanche photodetection extending up to 1.3 mu m. In an APD device operating at RT with a unity-gain responsivity of 0.2-0.25 A/W at similar to 5 V, the peak gain of 160 @ 1064 nm and 18 V reverse bias, gain >50 @ 1.3 mu m, are demonstrated. Thus, this work provides a foundation and prospects for exploiting greater freedom in NW photodiode design using hybrid axial and CS heterostructures.

Automated summary

We present the first study on a GaAs/GaAsSb core-shell-configured nanowire-based avalanche photodiode (APD) operating in the near-infrared (NIR) region. The nanowires consist of GaAs and GaAs1-xSbx with tunable band gap serving as the multiplication and absorption layers, respectively. This study successfully adopts various techniques to enhance the performance of the APD, such as doping compensation and segment-wise annealing. The results demonstrate a high gain and responsivity, making this design promising for future nanowire photodiode applications.