Low temperature grown GaNAsSb: A promising material for photoconductive switch application

Abstract

International audienceWe report a photoconductive switch using low temperature grown GaNAsSb as the active material. The GaNAsSb layer was grown at 200 °C by molecular beam epitaxy in conjunction with a radio frequency plasma-assisted nitrogen source and a valved antimony cracker source. The low temperature growth of the GaNAsSb layer increased the dark resistivity of the switch and shortened the carrier lifetime. The switch exhibited a dark resistivity of 107 Ω cm, a photo-absorption of up to 2.1 μm, and a carrier lifetime of ∼1.3 ps. These results strongly support the suitability of low temperature grown GaNAsSb in the photoconductive switch application

Study of a 1 eV GaNAsSb photovoltaic cell grown on a silicon substrate

“…GaNAsSb was first proposed by Ungaro et al 7 in 1999 as a potential GaAs-based small bandgap (<1.4 eV) material. It has been demonstrated as a promising material for optoelectronic devices, such as near infrared photodetectors [8][9][10] and photoconductive switches, 11,12 due to its capability to achieve a small energy bandgap, E g (0.8-1.2 eV), and to be lattice matched to a GaAs substrate.…”

Doping effects on the composition, electric and optical properties of MBE-grown 1.1 eV GaNAsSb layers

“…The beam equivalent pressure of the Sb flux was ̴ 1.2×10 -7 torr. Under these growth conditions, ̴ 2.4% of nitrogen and 6.5% of Sb were expected to incorporate into the GaNAsSb layers [11]. The nominal doping levels were determined by comparison of the dopant cell temperatures during GaAs and GaNAsSb doped layers growth.…”

Crystal structure of low-temperature-grown In0.45Ga0.55As on an InP substrate

“…LTG GaAs has a relatively good carrier mobility ($ 200 cm 2 /V s), an ultrashort carrier lifetime (o1 ps), and large resistivity ($ 10 7 Ω cm); therefore, the PCAs made of LTG GaAs are well suited to generate and detect THz waves using mode-locked Ti:sapphire lasers with wavelengths of approximately 0.8 μm. Recently, an attempt has been made to develop PCAs that can be excited by femtosecond fiber lasers with wavelengths of approximately 1.5 μm [1][2][3][4][5][6][7][8][9][10][11][12][13]. Because fiber lasers are portable and stable, using them to excite PCAs as a light source will allow less expensive and more compact THz-TDS systems to be used.…”

“…μm-region such as LTG-InGaAs [4,5,8,9], -GaNAsSb [11], and -GaAsBi [12,13] have been used. However, endeavors for these LTG-narrowbandgap semiconductors have not been completely successful.…”