We present in this work the effects of the rapid thermal annealing on the optical properties of InGaAsN single quantum wells grown on two different kind of misoriented GaAs (111)B substrates: 1° toward [-211] and 2° toward [2-1-1]. An increase of more than one order of magnitude of the photoluminescence emission is shown, as well as a shift towards higher energies of peak emission of the quantum well. This blueshift was found to be greater for the samples grown on the 2° misoriented substrates than for the first misorientation. These samples were grown by molecular beam epitaxy simultaneously, to assure tha same growth conditions for both samples. Different annealing temperatures were used to find the optimum optical properties for the InGaAsN quantum wells on GaAs (111)B. A comparison of the electrical characteristics of p-i-n diodes processed using as grown and annealed samples is presented. Finally, the application of the RTA optimization to InGaAsN laser devices grown on GaAs (111)B is presented.
The influence of carrier localization on the opto-electronic properties of GaInNAs/GaAs quantum well (QW) light emitting diodes (LED) and laser diodes (LD) grown by molecular beam epitaxy is studied. The external quantum efficiency of the LEDs at low temperature is found to be strongly affected by emission from localized states, and its evolution with the injected current is modified compared to the typical one of a QW LED. The light-current characteristics of GaInNAs LDs are measured for different temperatures between 15 and 295 K, and an anomalous behaviour of the threshold current with temperature is obtained comparing to a reference InGaAs laser. In particular, a negative or infinite T0 is obtained at very low temperatures, followed by a region of very small T0. In addition, if the temperature is further increased, a change to a higher T0 is obtained at a temperature which is in the range of the typical delocalization temperatures in GaInNAs QWs. All these features are attributed to the influence of carrier localization. The temperature induced changes in the relative carrier population of the localized states and the band edge states change the lineshape of the gain spectrum and its peak value, and consequently the threshold current of GaInNAs QW lasers.
In this work we show dilute nitride (InGaAsN and GaAsN) based laser diodes and detectors grown by Molecular Beam Epitaxy as good candidates to be used in optical fiber sensors applications. The maturity of GaAs technology allow us to develop laser devices less expensive and complex than the present InP based diodes which exhibit limited performances. Laser emission up to 1.23 μm is achieved for these devices. In addition, a new generation of (In)GaAsN quantum well intersubband detectors is also presented. This structures can be tailored to operate in a very short interval of wavelengths (namely 0.4 to 1 μm) centered in the range between 1.3 and 2 μm with a responsivity around 3 mA/W. The excellent selectivity of these detectors make them suitable to be matched with the emission wavelength of the source, thus avoiding the interference of external light sources. Both devices can be tuned to work in the range of interest for optical fibers, giving rise to a number of potential applications including Er-doped optical amplifiers, and optical fiber sensors.