[en] We report on the impact of thermal annealing to carrier transport and transient, subpicosecond photoresponse of freestanding GaAs mesostructures. Our measurements included micro-photoluminescence and dark current and responsivity studies as well as optical femtosecond characterization. The fabricated GaAs mesostructures consisted of both mesowires and platelets that were integrated into coplanar striplines to form a photoconductive switch. We demonstrate that an optimized annealing process of our mesostructures, performed at 600 ◦C for 20 min, led to restoring bulklike properties of our freestanding devices. They exhibited dark currents below 600 pA at 10 V bias, responsivity of 0.2 A W−1 at 30 V, and mobility as high as 7300 cm2 V s−1. The annealed freestanding GaAs photodetectors were characterized by subpicosecond carrier relaxation dynamics with negligible trapping and a cutoff frequency of 1.3 THz. The latter characteristics make them excellent candidates for THz-bandwidth optoelectronics.
Disciplines :
Physics
Author, co-author :
Mikulics, Martin; Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany
Hardtdegen, Hilde; Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany
Adam, Roman; Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany
Grützmacher, Detlev; Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany and Jülich-Aachen Research Alliance, JARA, Fundamentals of Future Information Technology, Germany
Gregušová, Dagmar; Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovakia
Novák, Jozef; Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovakia
Kordoš, Peter; Institute of Electrical Engineering, Slovak Academy of Sciences, SK-84104 Bratislava, Slovakia, and Department of Microelectronics, Slovak University of Technology, SK-81219 Bratislava, Slovakia
Sofer, Zdenĕk; Department of Inorganic Chemistry, Institute of Chemical Technology, Technická 5, Prague 6,Czech Republic
Serafini, J.; Department of Physics and Astronomy and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627, USA
Zhang, J.; Department of Electrical and Computer Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627, USA
Sobolewski, Roman; Department of Physics and Astronomy and Laboratory for Laser Energetics, and Department of Electrical and Computer Engineering and Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14627, USA
MARSO, Michel ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit
Language :
English
Title :
Impact of thermal annealing on nonequilibrium carrier dynamics in single-crystal, freestanding GaAs mesostructures
