Intersubband absorption and infrared photodetection at 3.5 and 4.2 μm in GaAs quantum wells

Abstract

We propose and demonstrate a novel concept for intersubband detectors at operating wavelengths of 3–5 μm using GaAs quantum wells. An extremely large intersubband spacing is obtained by using ultrathin AlAs barriers on either side of the GaAs quantum wells followed by a thicker Al0.3Ga0.7As layer. Simultaneously, the confining AlAs layers act as tunnel barriers which allow an electrical detection of the intersubband excitation.

Linear and Nonlinear Intersubband Optical Absorption in a Strained Double Barrier Quantum Well

“…Their theoretical results are in excellent agreement with experiment. Schneider et al [9,10] studied intersubband absorption in the context of infrared detection and modelled relevant transition energies by the transfer matrix method. Leroux et al [11] investigated confined electron states in AlGaAs/AlAs/GaAs DBQWs with ultrathin AlAs layers under high hydrostatic pressure.…”

Bound-to-extended state absorption in quantum wells confined by -like barriers

“…The temperature shift of the absorption peak is very small. The results are compared with experiments of Schneider et al [7,8] taking into account the broadening induced by well width fluctuations. …”

Electron Wave Function in the Field of One-Dimensional Irregular Layered Structure

“…As shown above, the problem of electron wave function determination in a layered structure field (2) in general reduces to solution of equation set (16), (17). The latter is a difficult mathematical problem that can be solved only in some specific cases.…”

“…Such a necessity arises, e.g., at investigation of optical absorption characteristics in semiconductor heterostructures, related to electron transit from bound state of discrete spectrum into a delocalized state of the continuous part of spectrum [17,18].…”