Material Gain in Ga0.66In0.34NyAs1–y, GaNyAs0.69–ySb0.31, and GaNyP0.46Sb0.54–y Quantum Wells Grown on GaAs Substrates: Comparative Theoretical Studies

Electronic band structure and material gain are calculated using the 8-band kp Hamiltonian for three quantum well (QW) systems grown on GaAs substrates: 1) Ga
_0.66
In
_0.34
N
_y
As
_1-y
/GaAs; 2) GaN
_y
As
_0.69-y
Sb
_0.31
/GaAs; and 3) GaN
_y
P
_0.46
Sb
_0.54-y
/GaAs QWs with various nitrogen concentrations. Bandgap and electron effective mass for Ga
_0.66
In
_0.34
N
_y
As
_1-y
, GaN
_y
As
_0.69-y
Sb
_0.31
, and GaN
_y
P
_0.46
Sb
_0.54-y
alloys are determined within band anticrossing model using the proper alloying approximations. The intensity and spectral position of gain peak are directly compared for QWs with 2% of nitrogen and 2% compressive strain in the QW layer. The largest shift of gain peak has been observed for GaN
_0.02
P
_0.46
Sb
_0.52
/GaAs QW. In this case, the gain peak (transverse electric (TE) mode) is located at 1.77 μm that is longer by 390 nm than the gain peak (TE mode) for Ga
_0.66
In
_0.34
N
_0.02
As
_0.98
/GaAs QW. In addition, for GaN
_0.02
As
_0.67
Sb
^0.31
/GaAs QW the largest shift of gain peak (TE mode) is observed for Ga
_0.66
In
_0.34
N
_0.02
As
_0.98
/GaAs QW (1.67 versus 1.38~μm. The intensities of TE modes of material gain are comparable for all three systems. The above indicates that GaN
_y
As
_0.69-y
Sb
_0.31
/GaAs and GaN
_y
P
_0.46
Sb
_0.54-y
/GaAs QW systems are promising candidates for GaAs-based lasers dedicated for emission in very long-wavelength telecommunication windows. The required nitrogen concentration for achieving gain peak position (TE mode) at 1.3 and 1.55~μm are 0.5% and 1.5% N for GaN
_y
As
_0.69-y
Sb
_0.31
/GaAs QWs, respectively, while for GaN
_y
P
_0.46
Sb
_0.54-y
/GaAs QWs are 0.3% and 1.2% N. Those values are significantly less than in Ga
_0.66
In
_0.34
N
_y
As
_1-y
/GaAs QWs. Considering a possible blue shift of QW emission upon annealing (i.e., the post grown procedure, which is usually used for improving optical quality of these QWs) the required nitrogen concentration can be larger by ~0.5% N than the one calculated for as-grown QWs.