A Study of Indium Nitride Films Grown Under Conditions Resulting in Apparent Band-gaps from 0.7 eV to 2.3 eV

2002 ◽  
Vol 743 ◽  
Author(s):  
K. S. A. Butcher ◽  
M. Wintrebert-Fouquet ◽  
Motlan ◽  
S. K. Shrestha ◽  
H. Timmers ◽  
...  
Keyword(s):  
Band Gap ◽  
Photoelectron Spectroscopy ◽  
Indium Nitride ◽  
Threshold Energy ◽  
Heavy Ion ◽  
Elastic Recoil ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
Direct Band ◽  
Band Tailing

ABSTRACTThe band-gap of indium nitride has long been believed to be about 1.9eV with slight variations due to band-tailing in polycrystalline samples and degenerate doping. Recently, other values as low as 0.7 eV have apparently been observed. We have compared samples spanning this apparent range of band-gap using secondary ion mass spectroscopy (SIMS), X-ray Photoelectron Spectroscopy (XPS) and heavy ion elastic recoil detection analysis (ERDA), in conjunction with spectral optical density measurements. Once structural inhomogeneiteies are taken into account, we show that much of the conflicting data are compatible with direct photoionisation with a threshold energy of about 1.0eV. This feature was first reported in polycrystalline indium nitride over 15 years ago and attributed to a ∣p> like defect state. We ask whether the feature may instead be a direct band-gap.

Composition and Structure of Epitaxial CaF2 Layers at the First Stages of Their Growth on Si(111)

2001 ◽  
Vol 696 ◽  
Author(s):  
R. Würz ◽  
W. Bohne ◽  
W. Fuhs ◽  
J. Röhrich ◽  
M. Schmidt ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Stoichiometric Composition ◽  
Interface Reaction ◽  
Heavy Ion ◽  
Interface Layer ◽  
Buffer Layers ◽  
Ex Situ ◽  
Elastic Recoil ◽  
Detection Analysis

AbstractCaF2 films with thicknesses in the monolayer range (<20 Å) were grown on Si(111) by evaporation from a CaF2 source at UHV conditions. They were characterized ex-situ by Heavy-Ion Elastic Recoil Detection Analysis (HI-ERDA), RBS/Channeling, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The F/Ca ratio of the films was found to depend on the growth temperature Ts and to deviate appreciably from the stoichiometric composition (F/Ca=2). Due to an interface reaction which leads to a CaF-interface layer a change from polycrystalline to epitaxial growth occurs at Ts=450°C. At higher temperature film growth started with a closed layer of CaF on top of which CaF2 layers with an increasing fraction of pinholes were formed. By means of a two-step process at different temperatures, the amount of pinholes could be strongly reduced. It was found, that buffer layers of CaF2 with a CaF interface layer introduced in Au/p-Si contacts enhance the barrier height by as much as 0.36eV to values of 0.64eV.

Heavy ion elastic recoil detection analysis set up for electronic sputtering studies

2006 ◽  
Vol 161 (4) ◽  
pp. 247-255 ◽  
Author(s):  
S. Ghosh ◽  
D. K. Avasthi ◽  
A. Tripathi ◽  
D. Kabiraj ◽  
P. Sugathan ◽  
...  
Keyword(s):  
Heavy Ion ◽  
Elastic Recoil ◽  
Elastic Recoil Detection Analysis ◽  
Elastic Recoil Detection ◽  
Detection Analysis ◽  
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