Experimental studies of lattice dynamical properties in indium nitride

Abstract

We review recent experimental studies on the lattice dynamical properties of novel semiconductor InN thin films. Most of the experimental results are concerned with Raman scattering as well as infrared spectroscopic studies. The emphasis is on the structure of Brillouin zone centre (Γ point) phonons in InN (including both the wurtzite and zinc blende structures), coupling between the electron excitation (plasmon) and the longitudinal optical phonon, disorder-activated modes, temperature- and pressure-dependences of the lattice vibration modes, micro-Raman imaging, and the lattice vibration in nitride alloys, superlattices, quantum wells, and quantum dots, etc. This article also presents some prospects on Raman scattering studies in the related materials and structures.

InN Thin Film Lattice Dynamics by Grazing Incidence Inelastic X-Ray Scattering

“…The recent realization of p-type doping [3,4] (in contrast to the commonly found n type) in InN has opened new possibilities for the achievement of highly efficient solar cells. Despite the intense research carried out on InN electronic and vibrational properties, there is a lack of experimental information on its phonon dispersion relations [5]. Usually grown by molecular beam epitaxy (MBE), state-of-the-art high quality InN films rarely exceed 10 m thickness, thus preventing the use of standard bulk techniques to measure phonon dispersion relations.…”

“…Usually grown by molecular beam epitaxy (MBE), state-of-the-art high quality InN films rarely exceed 10 m thickness, thus preventing the use of standard bulk techniques to measure phonon dispersion relations. The available InN experimental data stem therefore mainly from Raman and infrared spectroscopy [5,6], and new technical developments are required to complete this information over the entire Brillouin zone (BZ).…”

Structural and Morphological Characteristics of Inxga1-xN Films Grown on SI (111) by Reactive Magnetron Sputtering

“…When the temperature increases, In-N bond begins to split and In atoms will divorce from the film surface because the evaporated temperature of In is around 700 or more. The SEM morphology of In X Ga 1-X N samples with different temperature were shown in ସ point group symmetry structure (belong to wurtzite structure) [6], which is represented by A 1 (LO) and E 2 (high) modes. The silicon substrate peak at 520cm -1 is so strong that makes the E 2 (high) weakened.…”

Raman and transmission electron microscopy characterization of InN samples grown on GaN/Al2O3 by molecular beam epitaxy

“…The residual biaxial strain, induced only by the thermal contraction of the epilayers upon cooling, (Fig. 2(b)) has been estimated by using the relation ε(%) = (T g -T r ) × (α GaN -α InN ) × 100 [11], where T r = 21 °C is the room temperature, while α GaN = 5.59 × 10 -6 K -1 and α InN = 5.70 × 10 -6 K -1 [16] are the thermal expansion coefficients (along the a-axis of the wurtzite structure) of the template and the epilayer, respectively. Note that any other strain components, such as hydrostatic and/or uniaxial ones present, are not taken into account in this equation.…”