Sample C5 (2 ML s−1) emits at 1,270 nm with improved luminescence properties, showing an integrated Target Selective Inhibitor Library cell line intensity more than twice larger than that of sample B1, together with a PL line width of

only 39 meV. Longer wavelengths were achieved from samples with the CL grown at 1.5 ML s−1 (C4) and 1.2 ML s−1 (C3), emitting at 1,307 and 1,329 nm, respectively, but with a more deteriorated luminescence as the growth rate is reduced. By adding a higher Sb content to the CL grown at 2 ML s−1, it is also possible to reach peak wavelengths somewhat beyond 1.3 μm. Indeed, sample F2 emits at 1,308 nm, showing a significantly more intense luminescence than samples C3 and C4 with a narrower FWHM, which was hardly

widened when the temperature was increased from 15 K up to RT. This again points to the benefits provided by the highest growth rate, which allows achieving long emission wavelengths with improved luminescence properties. The obtained results represent the first step towards using GaAsSbN CLs in RT device applications. Figure 8 RT PL spectra for samples emitting around 1.3 μm. Conclusions The effect of modifying the growth conditions of the quaternary GaAsSbN CL on the PL properties of the InAs/GaAs QDs has been analyzed. click here Regarding growth temperature, 470°C was found to be the optimum value. A clear tendency was found when the CL thickness was modified, whereby the peak is red-shifted and the PL is degraded Dimethyl sulfoxide as the CL thickness increased. The best results were found when the CL growth rate was increased. The strong PL improvement at high growth rates up to 2 ML s−1 is shown to be specific for N-containing structures and likely related to a reduced composition modulation and plasma ion-induced

defect density. Nevertheless, a strict limitation regarding N incorporation is found when the CL is grown at 2 ML s−1, which forces one to remain at lower values in order to reach longer wavelengths. RT PL is obtained through different growth conditions, some of them leading to 1.3-μm emission. The best luminescence properties were found for the highest CL growth rate, being still possible to extend the emission wavelength by adding higher Sb contents. The obtained outcomes from the growth optimization of this system could represent a starting point from which the versatility of the GaAsSbN CL might be exploited for real device applications. Acknowledgements This work has been supported by Comunidad de Madrid through project P2009/ESP-1503 and by the EU (COST ActionMP0805). Jose M Ulloa was supported by the Spanish MICINN through the ‘Ramón y Cajal’ program. References 1. Akahane K, Yamamoto N, Ohtani N: Long-wavelength light emission from InAs quantum dots covered by GaAsSb grown on GaAs substrates. Physica E 2004, 21:295–299.CrossRef 2.