Performance Enhancement of a GaAs Detector with a Vertical Field and an Embedded Thin Low-Temperature Grown Layer

Sensors

关键词: photodetector;    photodiode;    GaAs;    low-temperature grown GaAs;    electro-optic sampling;    ultrafast detector;    heterojunction;    Schottky contact;   

DOI  :  10.3390/s130202475

来源: DOAJ

【 摘 要 】

Low temperature growth of GaAs (LT-GaAs) near 200 °C results in a recombination lifetime of nearly 1 ps, compared with approximately 1 ns for regular temperature ~600 °C grown GaAs (RT-GaAs), making it suitable for ultra high speed detection applications. However, LT-GaAs detectors usually suffer from low responsivity due to low carrier mobility. Here we report electro-optic sampling time response measurements of a detector that employs an AlGaAs heterojunction, a thin layer of LT-GaAs, a channel of RT-GaAs, and a vertical electric field that together facilitate collection of optically generated electrons while suppressing collection of lower mobility holes. Consequently, these devices have detection efficiency near that of RT-GaAs yet provide pulse widths nearly an order of magnitude faster—~6 ps for a cathode-anode separation of 1.3 μm and ~12 ps for distances more than 3 μm.

【 授权许可】

Unknown