TY - JOUR
T1 - Long-wavelength infrared spectroscopy of an asymmetrically structured Ga0.6Al0.4As/GaAs superlattice
AU - Borenstain, Shmuel I.
AU - Gravé, Ilan
AU - Larsson, Anders
AU - Rich, Daniel H.
AU - Jonsson, Bjorn
AU - Andersson, Ingmar
AU - Westin, Johan
AU - Andersson, Thorwald
PY - 1991/1/1
Y1 - 1991/1/1
N2 - A long-wavelength infrared (LWIR) spectroscopic study of a doped multiple-quantum-well (MQW) structure, where each quantum well is clad by asymmetrically structured superlattices, is reported. The measured absorption and photocurrent spectra differ markedly from those of a MQW LWIR detector with conventional flat barriers. Different electron subband states are introduced, and the transition e1-e3, which in a flat-barrier MQW is normally forbidden, becomes the dominant transition; thus bringing about an extremely broad photoresponse band (/0.6), centered at 5 m. This system also exhibits direct evidence of photon-assisted resonant tunneling. It is manifested by a distinct peak and negative differential photoconductance in the photocurrent-vs-bias- voltage characteristics when the structure is exposed to a CO2 9.5-m laser line. All these effects are explained by the dependence of the electronic eigenstate spectrum on the electric field, calculated by solving the Schrödinger equation using the transfer-matrix method.
AB - A long-wavelength infrared (LWIR) spectroscopic study of a doped multiple-quantum-well (MQW) structure, where each quantum well is clad by asymmetrically structured superlattices, is reported. The measured absorption and photocurrent spectra differ markedly from those of a MQW LWIR detector with conventional flat barriers. Different electron subband states are introduced, and the transition e1-e3, which in a flat-barrier MQW is normally forbidden, becomes the dominant transition; thus bringing about an extremely broad photoresponse band (/0.6), centered at 5 m. This system also exhibits direct evidence of photon-assisted resonant tunneling. It is manifested by a distinct peak and negative differential photoconductance in the photocurrent-vs-bias- voltage characteristics when the structure is exposed to a CO2 9.5-m laser line. All these effects are explained by the dependence of the electronic eigenstate spectrum on the electric field, calculated by solving the Schrödinger equation using the transfer-matrix method.
UR - http://www.scopus.com/inward/record.url?scp=35949010988&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.43.9320
DO - 10.1103/PhysRevB.43.9320
M3 - Article
AN - SCOPUS:35949010988
SN - 0163-1829
VL - 43
SP - 9320
EP - 9323
JO - Physical Review B
JF - Physical Review B
IS - 11
ER -