Investigation of the optical properties of GaAs with δ-Si doping grown by molecular-beam epitaxy at low temperatures

Abstract

Molecular beam epitaxy is used for the preparation of structures based on "low temperature" grown GaAs with introduced δ Si doping. Specific features in the photon energy range of 1.28-1.48 eV are observed in the photoluminescence spectrum after structures annealing at temperatures of 520 and 580°C; these features are related to the formation of point defects and their complexes. The "pump-probe" light transmission measurements reveal that the characteristic lifetimes of nonequilibrium carriers in the fabri cated structures amount to τ c ≈ 1.2-1.5 ps.

Low temperature photoluminescence study of GaAs defect states*

“…[2] For this reason, the identification and characterization of defects in GaAs substrate, as well as the understanding of their optical and thermodynamical properties, are very important and remain an active research field. [3][4][5][6][7] There are six elementary native point defect species in GaAs substrate: vacancies in the Ga sublattice (V Ga ), vacancies in the As sublattice (V As ), Ga selfinterstitials (I Ga ), As self-interstitials (I As ), antisite defects formed by a Ga atom on an As site (Ga As ) and an As atom on a Ga site (As Ga ). [8] V As and Ga As are at E C − 0.145 eV and E V + 0.078 eV, respectively.…”

Intensive Terahertz Radiation from InXGa1-XAs due to Photo-Dember Effect

“…For comparison we also grew and investigated LT GaAs with heavily doped n-GaAs buffer layer. Previously 5 we have shown that LT GaAs grown by MBE with several thin -Si doped layers embedded into the photoconductive layer GaAs exhibits picosecond carrier lifetimes. Authors in Ref.…”

New Materials and Structures for Efficient Terahertz (THz) Spectroscopy

“…The basic semiconductor, silicon-on-sapphire, on which they were formed, was replaced by GaAs grown at low temperatures [6][7][8]. At later stages, other materials were used, for example InGaAs [9], InAlAs, and GaBiAs [10] alloys, and materials based on graphene [11].…”

“…One of the most advanced materials is the InGaAs photoconductor. This material allows application of lasers working within the range 1.0-1.6 μm [10,[12][13][14] for optical pumping. However, application of InGaAs is fraught with difficulties.…”