Intersubband absorption in n-doped InAs/AlSb multiple-quantum-well structures

Abstract

Well-thickness dependence of intersubband absorption energies is investigated in n-doped InAs/AlSb multiple-quantum-well structures grown by molecular-beam epitaxy. Decreasing the InAs well thickness from 18 to 9 monolayers, the absorption peak shifts from 3.31 μm (375 meV) to 1.98 μm (627 meV). These absorption energies are found to be larger than those of the corresponding spatially indirect band gap between the electron ground state in the InAs well and the heavy-hole ground state in the AlSb barrier. Intersubband transition energies are calculated self-consistently using multiband k⋅p calculation combined with Poisson equation, and compared with the experimental results.

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

“…m 1.01 4 λ = μ ). Similarly, Ohtani et al [32] have experimentally studied the well thickness dependence of inter-subband absorption energies in n-doped InAs/AlSb multiple quantum wells grown by molecular beam epitaxy. They reported that the absorption peak shifts to lower energies with increasing the well thickness for a fixed in-plane doping density.…”

Transformation of type‐II InAs/AlSb nanoscale heterostructure into type‐I structure and improving interband optical gain

“…However, the increase in optical gain due to increase range in applied pressure has also been observed in type‐I n‐AlGaAs/GaAs/p‐AlGaAs nano‐heterostructures . According to a literature survey, there are many research papers on the InAs/AlSb material system which focus on inter‐subband transitions along with their possible applications in the area of optoelectronics and photonics working in MWIR wavelength region . Unfortunately, interband transitions in such a heterostructure have not been utilized in device applications in the area of optoelectronics, while photoluminescence on narrow InAs/AlSb type‐II heterostructures has been reported in the near infra‐red (NIR) region .…”

Doping-induced type-II to type-I transition and mid-IR optical gain in InAs/AlSb quantum wells

“…While photoluminescence has been measured for InAs QWs, 1-4 yet there has not been a device application based on interband transitions. Most of recent papers on this material system focus on intersubband transitions [5][6][7] and possible device applications in the MWIR and THz wavelength ranges. This paper is an extension of our recent work 8 where we showed that doping of the AlSb layers on both sides of an InAs layer (modulation doping) will convert this InAs layer from a barrier to a well for holes, thus converting a type-II heterostructure into a type-I due to the associated band bending.…”