Inducing normally forbidden transitions within the conduction band of GaAs quantum wells

Abstract

Six heretofore unobserved envelope state transitions within the conduction band of an AlAs/GaAs quantum well are reported, two of which are forbidden in a symmetric quantum well. The highest energy transition is resonant with 2.86 μm wavelength light. These resonant energies and absorption strengths agree with predictions based on a many-body theory of electrons in nonparabolic energy bands. A new type of infrared modulator is possible via absorption changes in the ‘‘forbidden’’ transition between the first and the third conduction subbands.

Quantum scattering engineering of quantum well infrared photodetectors in the tunneling regime

“…Usually the doping is located in the central part of the well in QWIP. The effect of the doping position on the spectral response has also been studied by Dupont et al 12 for the control of the transition linewidth and by Pan et al 13 for the possibility to observe forbidden transitions. In order to solve doping segregation problems, Schneider et al 8,9 have proposed to move the doping away from its central position to the first part of the well.…”

n doping effect modeling in 1.3 μm GaN0.58As1−1.58Bi /GaAs quantum wells

“…Besides, we have also investigated the effect of n-doped region on the electronic and optical properties of GaNAsBi/GaAs QWs [18]. On the other hand, various investigations reported the doping effect on radiatives transitions, oscillator strength and absorption coefficient for standard QWs such as AlAs/GaAs and AlGaAs/GaAs [19][20][21] GaN x As 1 À x À y Bi y /GaAs QWs.…”

Detection wavelength of InGaAs/AlGaAs quantum wells and superlattices

“…2 In another extreme, with xϭ1, an absorption wavelength as short as 2.9 m was reported. 3 However, a high Al molar ratio is less desirable in detector applications. Besides the presence of higher defect density, the energy crossing of the ⌫ and X valleys at xу0.45 reduces the thermal activation energy of the ground state electrons.…”