InN Samples (inn + sample)

Distribution by Scientific Domains


Selected Abstracts


Detection of non-equilibrium longitudinal optical phonons in InN and its consequences

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005
W. Liang
Abstract Picosecond Raman spectroscopy has been used to study properties of non-equilibrium longitudinal optical phonons in a high quality, single crystal wurtzite structure InN sample. Our experimental results show that the bandgap of InN cannot be around 1.89 eV; but are consistent with a bandgap of around 0.8 eV. Our results provide a concrete evidence that 0.8 eV-luminescence observed recently in InN cannot be due to deep level radiative emission in InN. ( 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


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

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2006
J. Arvanitidis
Abstract Raman spectroscopy and transmission electron microscopy were employed to study the vibrational properties and the microstructure of epitaxially grown InN films on GaN/Al2O3 templates. The variations of the InN lattice constants, as deduced by electron diffraction analysis, along with the red-shifted E22 mode frequency reveal that InN films exhibit residual tensile stress, strongly dependent on the epilayer growth temperature. Threading dislocations are the dominant structural defects in the films, having a density in the order of 109,1010 cm,2. Profile analysis of the E22 Raman peak by means of the Spatial Correlation Model provides useful information concerning the effective mean length for free phonon propagation (L), which is a measure of the structural quality of the samples. In all the studied samples, L monotonically increases with decreasing threading dislocation density of pure screw and mixed type character. ( 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Self-organized growth of InN-nanocolumns on p-Si(111) by MBE

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008
Christian Denker
Abstract InN-nanocolumns are an attractive system for light harvesting applications. To understand the mechanism of self organized growth of nanocolumns in plasma assisted MBE, InN samples were produced under various conditions on p-Si(111). Depending on the growth parameters different growth regimes for nanocolumns were identified according to their final shape. High-resolution TEM pictures show a very good crystal quality. This is also confirmed by Raman and PL measurements. Nanocolumns with diameters of 20-200 nm and lengths of up to 2 mm were produced. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Carrier-induced refractive index change in InN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2008
C. Bulutay
Abstract Rapid development of InN technology demands comprehensive assessment of the electronic and optoelectronic potential of this material. In this theoretical work the effect of free electrons on the optical properties of the wurtzite phase of InN is investigated. The blue shift of the optical absorption edge by the free-carrier band filling is known as the Burstein-Moss effect for which InN offers to be a very suitable candidate as has been recently demonstrated experimentally. Due to well known Kramers-Kronig relations, a change in absorption is accompanied by a change in the index of refraction. Considering n-type InN samples with free electron concentrations ranging from 51017 to 51020 cm,3, and employing a nonlocal empirical pseudopotential band structure, it is shown that this leads to a few percent change of the index of refraction. These carrier-induced refractive index changes can be utilized in optical switches, futhermore it needs to be taken into account in the design of InN-based optical devices such as lasers and optical modulators. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Non-stoichiometry and non-homogeneity in InN

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2005
K. Scott
Abstract It is shown that the wide variation of apparent band-gap observed for thin films nominally referred to as InN is strongly influenced by variations in the nitrogen:indium stoichiometry. InN samples grown by remote plasma enhanced chemical vapour deposition show a change in band-gap between 1.8 and 1.0 eV that is not due to the Moss-Burstein effect, oxygen inclusion or quantum size effects, but for which changes in the growth temperature result in a strong change in stoichiometry. Material non-homogenity and non-stoichiometry appear to be general problems for InN growth. Excess nitrogen can be present at very high levels and indium rich material is also found. This work shows that the extent of the Moss-Burstein effect will have to be reassessed for InN. ( 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]