Methylamine Growth of SiCN Films Using ECR-CVD

1999 ◽  
Vol 606 ◽  
Author(s):  
C.-Y. Wen ◽  
J.-J. Wu ◽  
H.J. Lo ◽  
L.C. Chen ◽  
K.H. Chen ◽  
...  

AbstractContinuous polycrystalline SiCN films with high nucleation density have been successfully deposited by using CH3NH2, as carbon source gas in an ECR-CVD reactor. Fom the kinetic point of view, using CH3NH2, as carbon source could provide more abundant active carbon species in the gas phase to enhance the carbon incorporation in the SiCN films. The compositions of the SiCN films analyzed from Rutherford Backscattering Spectroscopy showed that higher [CH3NH2,]/[SiH4] ratio led to higher carbon content in the films. Moreover, a lower carbon content was measured when the film was deposited at higher substrate temperature. The direct band gap of the aforementioned SiCN films determined using PzR is around 4.4 eV, indicating a wide band gap material for blue-UV optoelectronics.

2013 ◽  
Vol 22 ◽  
pp. 346-350
Author(s):  
K. RAVINDRANADH ◽  
R. V. S. S. N. RAVIKUMAR ◽  
M. C. RAO

CdSe is an important II-VI, n-type direct band gap semiconductor with wide band gap (bulk band gap of 2.6 eV) and an attractive host for the development of doped nanoparticles. Poly vinyl alcohol (PVA) is used as a capping agent to stabilize the CdSe nanoparticles. The optical properties of Co (II) ion doped PVA capped CdSe nanoparticles grown at room temperature are studied in the wavelength region of 200-1400 nm. The spectrum of Co (II) ion doped PVA capped CdSe nanoparticles exhibit five bands at 1185, 620, 602, 548 and 465 nm (8437, 16125, 16607, 18243 and 21499 cm-1). The bands observed at 1185, 548 and 465 nm are correspond to the three spin allowed transitions 4T1g (F) → 4T2g (F), 4T1g (F) → 4A2g (F) and 4T1g (F) → 4T1g (P) respectively. The other bands observed at 602 nm and 620 nm are assigned to spin forbidden transitions 4T1g (F) → 2T2g (G), 4T1g (F) → 2T1g (G) . The small value of the Urbach energy indicates greater stability of the prepared sample.


2017 ◽  
Vol 24 (34) ◽  
pp. 26792-26805 ◽  
Author(s):  
Marcin Jędrzejczyk ◽  
Klaudia Zbudniewek ◽  
Jacek Rynkowski ◽  
Valérie Keller ◽  
Jacek Grams ◽  
...  
Keyword(s):  
Band Gap ◽  

1995 ◽  
Vol 395 ◽  
Author(s):  
Z.-J. Tian ◽  
M.W.C. Dharma-Wardana ◽  
L.J. Lewis

ABSTRACTWide bandgap III-V nitrides, such as GaN and AlN, have become topical in the near-term technology of blue lasers. We report detailed electronic band-structure calculations for (AlN)m(GaN)n [001] zinc-blende superlattices (SL), with m + n ≤ 12, using the all-electron full-potential linear-muffin-tin-orbital method. For n ≥ 3, the SL are found to have a direct band gap. For n ≤ 2 and m ≥ 3, all the band gaps are indirect. In ultrathin SL, m ≤ 3 and n ≤ 2, only (m, n)= (3,1) is found to have an indirect gap. The band offsets are estimated by calculating the core-level shifts of nitrogen atoms in the central planes of the GaN and A1N layers. The calculated densities of states, electron- and hole- effective masses (m), etc., as a function of m and n, are reported; a remarkable dependence of m on the number of layers is revealed.


Author(s):  
T. D. Musho ◽  
S. M. Claiborne ◽  
D. G. Walker

Recent studies of wide band-gap diamond field emission devices have realized superior performance and lifetime. However, theoretical studies using standard Fowler-Nordheim (FN) theory do not fully capture the physics of diamond semiconductor emitters as a result of the fitting parameters inherent to the FN approximation. The following research computationally models wide band-gap field emission devices from a quantum point of view, using a novel non-equilibrium Green’s function (NEGF) approach previously applied to modeling solid-state electronic devices. Findings from this research confirm non-linearities in the FN curve and provide alternative explanations to discrepancies between standard FN theory.


2016 ◽  
Vol 12 (4) ◽  
pp. 462-467 ◽  
Author(s):  
Dong-Won Kang ◽  
Porponth Sichanugrist ◽  
Bancha Janthong ◽  
Muhammad Ajmal Khan ◽  
Chisato Niikura ◽  
...  

2010 ◽  
Vol 24 (20) ◽  
pp. 2187-2193 ◽  
Author(s):  
M. P. GHIMIRE ◽  
SANDEEP ◽  
R. K. THAPA

CrO 2 has a wide band gap for "down" spins and the Fermi level lies in the middle of the band gap. Calculations based on the local-spin density approximation (LSDA) has been performed to investigate the electronic and physical properties of CrO 2 in the rutile structure (P42/mnm). We considered the semicore electrons as valence electrons and found that CrO 2 appears to be half-metallic with a direct band gap of 1.8 eV in spin-down and has metallic behavior in spin-up configurations.


Author(s):  
Joanna L. Batstone

Interest in II-VI semiconductors centres around optoelectronic device applications. The wide band gap II-VI semiconductors such as ZnS, ZnSe and ZnTe have been used in lasers and electroluminescent displays yielding room temperature blue luminescence. The narrow gap II-VI semiconductors such as CdTe and HgxCd1-x Te are currently used for infrared detectors, where the band gap can be varied continuously by changing the alloy composition x.Two major sources of precipitation can be identified in II-VI materials; (i) dopant introduction leading to local variations in concentration and subsequent precipitation and (ii) Te precipitation in ZnTe, CdTe and HgCdTe due to native point defects which arise from problems associated with stoichiometry control during crystal growth. Precipitation is observed in both bulk crystal growth and epitaxial growth and is frequently associated with segregation and precipitation at dislocations and grain boundaries. Precipitation has been observed using transmission electron microscopy (TEM) which is sensitive to local strain fields around inclusions.


Author(s):  
Raquel Caballero ◽  
Leonor de la Cueva ◽  
Andrea Ruiz-Perona ◽  
Yudenia Sánchez ◽  
Markus Neuschitzer ◽  
...  

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