Structural effects of the thermal treatment on a GaInNAs/GaAs superlattice

Abstract

We have studied structural changes that occur during annealing of GaInNAs/GaAs multiple quantum wells grown by metalorganic vapor-phase epitaxy (MOVPE). Different thermal treatments led to an improved room-temperature photoluminescence (PL) intensity, but also to room-temperature PL peak splitting. This splitting is related to the appearance of compositional clustering as displayed by transmission electron microscopy (TEM). In addition to this, interfacial layers on each side of the wells have also been observed by TEM and their composition is discussed on the basis of high resolution x-ray diffraction studies. It is suggested that the interface layers are indium deficient, but enriched in nitrogen, degrading the optical quantum well performance and indicating a need for improved switching sequences in the MOVPE growth.

Anomalous temperature-dependent photoluminescence characteristic of as-grown GaInNAs/GaAs quantum well grown by solid source molecular beam epitaxy

“…The localized transitions could be contributed by several factors, such as composition fluctuation of the GaInNAs alloy, or QW-barrier interface roughness, N localization, or a combination of the above [32][33][34][35]. For the first two factors, the composition fluctuation was observed in transmission electron microscopy (TEM) as undulation pattern across the GaInNAs alloy layer [36]. It was also reported that in the GaInNAs alloy, there could be high local In or N composition as a result of clustering during growth, and hence resulted in the above localized transitions [37].…”

Red shift in the photoluminescence of indium gallium arsenide nitride induced by annealing in nitrogen trifluoride

“…The annealing affects the PL in two ways. One is a strong enhancement of the radiative efficiency, which is commonly observed in annealing studies [5][6][7][8][9][10][11][12][13][14][15][16]. The other is a red shift of the InGaAsN peak position from 923 nm at 370 1C to 948 nm at 530 1C.…”

“…In few cases where heating was carried out above 650 1C, the PL efficiency was reduced due to surface degradation. The improvement in PL efficiency after heat treatments is attributed to a reduction of non-radiative centers associated with the nitrogen incorporation [5,6]. Aside from improving PL efficiency, the heat treatments usually shift the emission to lower wavelengths.…”

“…Nonetheless, its usefulness may be limited by the optical quality of the film. Annealing InGaAsN/GaAs quantum wells (QWs) and superlattices (SLs) in AsH 3 or N 2 has been shown to improve the photoluminescence (PL) by removing non-radiative centers [5,6]. In addition, the heat treatment commonly causes a blue shift in wavelength.…”

Modified atomic scattering amplitudes and size effects on the 002 and 220 electron structure factors of multiple Ga1−xInxAs/GaAs quantum wells

“…However, the agreement of the HF results with our DFT calculations for scattering vectors larger than 0.3 Å −1 encourages the use of the DT results for higher order reflection like the 220 and 004 reflections. [28][29][30][31] Another important aspect of the DFT result is the orientation sensitivity at small scattering vectors. In Fig.…”