%0 Journal Article
%T Performance Enhancement of a GaAs Detector with a Vertical Field and an Embedded Thin Low-Temperature Grown Layer
%A Marc Currie
%A Pouya Dianat
%A Anna Persano
%A Maria Concetta Martucci
%A Fabio Quaranta
%A Adriano Cola
%A Bahram Nabet
%J Sensors
%D 2013
%I MDPI AG
%R 10.3390/s130202475
%X Low temperature growth of GaAs (LT-GaAs) near 200 ¡ãC results in a recombination lifetime of nearly 1 ps, compared with approximately 1 ns for regular temperature ~600 ¡ãC 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¡ª~6 ps for a cathode-anode separation of 1.3 ¦Ìm and ~12 ps for distances more than 3 ¦Ìm.
%K photodetector
%K photodiode
%K GaAs
%K low-temperature grown GaAs
%K electro-optic sampling
%K ultrafast detector
%K heterojunction
%K Schottky contact
%U http://www.mdpi.com/1424-8220/13/2/2475