ABSTRACT
This chapter discusses the morphology and the composition of highly strained InGaAs and InGaAsN layers using 002 dark-field image contrast and the selected area electron diffraction technique. The images show the presence of two symmetrical interfacial layers around the wells. Higher indium composition increases the compressive strain to a critical point for the structural quality of the layer. The incorporation of nitrogen decreases the lattice parameter of the alloy and red-shifts its wavelength. The optical properties of the alloys are degradated with the nitrogen incorporation. High N composition can introduce non-radiative centers. The chapter examines the morphology and the composition ofinGaAs and InGaAsN layers using 002 and 220 dark-field image contrast and by selected area electron diffraction. The InGaAs/GaAs as well as the InGaAsN/GaAs heterostructures show systematically the presence of thin intermediate layers at the interfaces.
