Interband transitions of quantum wells and device structures containing Ga(N, As) and (Ga, In)(N, As)

Abstract

The unusual N-induced band formation and band structure of Ga(N, As) and (Ga, In)(N, As) alloys are also reflected in the electronic structure of quantum wells (QWS) and device structures containing these non-amalgamation-type alloys. This review is divided into three parts. The first part deals with band structure aspects of bulk Ga(N, As) and motivates the possibility of a k•p-like parameterization of the band structure in terms of the level repulsion model between the conduction band edge of the host and a localized N-level. The second part presents experimental studies of interband transitions in Ga(N, As)/GaAs and (Ga, In)(N, As)/GaAs QW structures addressing band offsets, electron effective mass changes and an intrinsic mechanism contributing to the blueshift of the (Ga, In)(N, As) band gap on annealing. The observed interband transitions can be well described using a ten-band k•p model based on the level repulsion scheme. The third part deals with (Ga, In)(N, As)-based laser devices. The electronic structure of the active region of vertical-cavity surface-emitting laser and edge-emitter laser structures is studied by modulation spectroscopy. The gain of such structures is measured by optical methods and analysed in terms of a model combining the ten-band k•p description of the band structure and generalized Bloch equations.

Pressure and k · p studies of band parameters in dilute‐N GaInNAs/GaAs multiple quantum wells

“…The arrows indicate the effective band gap for each sample (obtained by least-squares fitting using Aspnes's lineshape model [7]). Examination of the data clearly reveals two trends as a function of increasing N-content: i) a rapid red-shift in the transition energies similar to the results found in prior studies on thick In y Ga 1-y As 1-x N x epilayers [3] and on a variety of dilute-N III-V MQWs [2]; (ii) a strong broadening in the line-shapes: this indicates that adding N increases the inhomogeneous broadening of the QW transitions [4].…”

“…In this new class of dilute-N III-N-V semiconductor alloys, modification in the band structure is achieved by N forming localised states which interact with the conduction band (CB) edge of the host semiconductor [3]. To investigate this complex band formation, modulation spectroscopy as a function of pressure, has proved to be a very useful tool [2][3][4]. Previously we reported the dramatic effects of increasing N-incorporation on the quantum well (QW) interband energies including negative bandgap-bowing, smaller total temperature variation, and strong decrease in the rate of pressure-shift (reduced linear shifts with larger sub-linear components) [4].…”

“…InGaNAs differs considerably from the conventional III-V alloys and exhibits striking new properties [2], some of which are reviewed in this paper. In this new class of dilute-N III-N-V semiconductor alloys, modification in the band structure is achieved by N forming localised states which interact with the conduction band (CB) edge of the host semiconductor [3].…”

New Developments in Dilute Nitride Semiconductor Research

“…Detailed studies on the nearest-neighbor environment of the substitutional N atoms in GaInNAs have shown that the fundamental band-gap energy in quaternary dilute nitride alloys is fairly sensitive to the local environmental conditions especially in the case of quantum well structures. 65,66 A more complicated modeling of the electronic structure based on pseudopotentials 67,68 requires a substantial computational effort. The numerical results are difficult to use.…”

Theory of electron confinement and electron effective mass in dilute nitride alloys and heterostructures

“…The two approaches have been highly successful in describ-ing the band edge energies, and their variation upon annealing [17,18]. The BAC model has also been successfully applied to interpret photoreflectance (PR) measurements both of bulk and quantum well (QW) GaNAs samples at room temperature, identifying a higher energy feature (E + ) observed in bulk samples [16,19,20], and also providing a consistent interpretation of quantum well excited state transition energies across a wide range of samples, and as a function of hydrostatic pressure [21,22]. Despite the wide success of the BAC model, there has until recently been one significant set of experimental data which has remain unexplained, namely the observed composition dependence of the conduction band edge (CBE) effective mass in Ga(In)NAs alloys, in particular, at low temperatures.…”