n-Type GaAs/AlGaAs heterostructure detector with a 3.2 THz threshold frequency.
Terahertz detection using the free-carrier absorption requires a small internal work function of the order of a few millielectron volts. A threshold frequency of 3.2 THz (93 microm or approximately 13 meV work function) is demonstrated by using a 1 x 10(18) cm(-3) Si-doped GaAs emitter and an undoped Al(0.04)Ga(0.96)As barrier structure. The peak responsivity of 6.5 A/W, detectivity of 5.5 x 10(8) Jones, and quantum efficiency of 19% were obtained at 7.1 THz under a bias field of 0.7 kV/cm at 6 K, while the detector spectral response range spans from 3.2 to 30 THz.
Weerasekara
Aruna
A
Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
Rinzan
Mohamad
M
Matsik
Steven
S
Perera
A G
AG
Buchanan
Margaret
M
Liu
Hui Chun
HC
von Winckel
Greg
G
Stintz
Andreas
A
Krishna
Sanjay
S