Structural characterization of GaN nanowires using TEM

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2018, Tutores: Gemma Martín, Francesca Peiro In the present study, gallium nitride (GaN) nanowires fabricated by top-down etching are investigated by transmission electron microscopy (TEM). The study starts with the lamella preparation using the lift-out technique in a focused ion beam (FIB) instrument. Subsequently, different observation modes of the TEM are applied to asses the quality of the growth and identify the crystal structure. Selected area diffraction mode (SAD) is used to obtain the diffraction patterns, which are appropriate to identify the crystal structure. Then, two-beam conditions are carried out to find the crystallographic defects and, Finally, through the high resolution mode, the phase contrast images are used to achieve atomic resolution.