title: Performance enhancement of a GaAs detector with a vertical field and an embedded thin low-temperature grown layer.
abstract: 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.
authors: Optical Sciences Division, U.S. Naval Research Laboratory, Washington, DC 20375, USA. marc.currie@nrl.navy.mil
authors: Marc
authors: M
authors: Currie
authors: Pouya
authors: P
authors: Dianat
authors: Anna
authors: A
authors: Persano
authors: Maria Concetta
authors: MC
authors: Martucci
authors: Fabio
authors: F
authors: Quaranta
authors: Adriano
authors: A
authors: Cola
authors: Bahram
authors: B
authors: Nabet