Fabrication and optical constants of amorphous copper nitride thin films prepared by ion beam assisted dc magnetron reactive sputtering

Odeh, I. M.

doi:10.1016/j.jallcom.2006.12.020

Cited by 27 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The optical band gap E g is another important quantity that characterizes semiconductors and dielectric materials because it has a considerable significance in the design and modeling of such materials . The optical band gap was derived from the intercept of the extrapolated liner part of the plot of (α E ) p versus the photon energy E with abscissa.…”

Section: Optical Propertiesmentioning

confidence: 99%

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

2013

View full text Add to dashboard Cite

Structural, elastic, optical, thermodynamical, and electronic properties of yttrium oxide compound in cubic phase have been studied using the full-potential augmented plane waves (FP-LAPW) within density functional theory (DFT) framework. Four different approximations were used for exchange-correlation potentials terms, comprised Perdew-Burke-Ernzerhof generalized parameterization of gradient approximation (GGA-PBE), Wu-Cohen (WC-GGA), localdensity approximation (LDA), and new approximation modified Becke and Johnson (mBJ-GGA). The structural properties such as equilibrium lattice parameter, bulk modulus and its pressure derivative have been obtained using optimization method. Moreover, Elastic constants, Young's modulus, shear modulus, Poisson's ratio, sound velocities for longitudinal and shear waves, Debye average velocity, Debye temperature, and Gr€ uneisen parameters have been calculated. Obtained structural, elastic and other parameters are consistent with experimental data. Moreover pressure dependence of the elastic moduli was studied. From electronic calculations, it has been found that the band gap was 5.7 eV at Г point in the Brillouin zone using mBJ-GGA approximation. Optical properties, such as the dielectric function, refractive index, extinction index, and optical band gap, were calculated for radiation up to 14 eV. In addition, the unique type of bonding in Y 2 O 3 was discussed by three method including effective charge, B/G ratio, and charge density distribution.

show abstract

Section: Optical Propertiesmentioning

confidence: 99%

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

2013

View full text Add to dashboard Cite

show abstract

“…Cu 3 N has been obtained by a variety of methods including sputtering, ,− molecular beam epitaxy, atomic layer deposition, , and pulsed laser deposition. , Recently, Matsuzaki et al have obtained Cu 3 N from Cu under NH 3 and O 2 between 500 and 800 °C. However, in the past, most have obtained Cu 3 N by sputtering of Cu under N 2 in conjunction with Ar, which enables control over its stoichiometry.…”

Section: Introductionmentioning

confidence: 99%

Observation of the Direct Energy Band Gaps of Defect-Tolerant Cu₃N by Ultrafast Pump-Probe Spectroscopy

et al. 2020

View full text Add to dashboard Cite

Cu 3 N with a cubic crystal structure has been prepared from Cu on fused SiO 2 under a flow of NH 3 :O 2 between 400 and 600 °C. All Cu 3 N layers exhibited distinct maxima in differential transmission at ∼500, 550, and 630, 670 nm with the same spectral structure and shape on a ps timescale as shown by ultrafast pump-probe spectroscopy. We show that the maxima at 630 (≡1.97 eV) and 670 nm (≡1.85 eV) correspond to the M and R direct energy band gaps of Cu 3 N, in excellent agreement with density functional theory calculations of the electronic band structure. These findings are corroborated further by the fact that Cu 3 N as-deposited by reactive sputtering under 100% N 2 at 25 °C and 10 −2 mbar did not exhibit a fine spectral structure due to a smeared density of states, poor crystallinity, and a high density of defects, but annealing under NH 3 :H 2 at 300 °C revealed a similar spectral structure to Cu 3 N obtained from Cu under NH 3 :O 2 . In contrast to the above, we suggest that the peaks at 500 (≡2.48 eV) and 550 nm (≡2.25 eV) might correspond to the M and R direct gaps of certain regions of Cu 3 N under strain that changes the lattice constant and band gap. We discuss the charge carrier generation and recombination mechanisms in terms of Cu interstitials and vacancies that are known to be energetically located near the band edges, thus allowing the observation of the direct energy band gaps in this defect tolerant semiconductor.

show abstract

“…Some spread is apparent in various physical properties reported for Cu 3 N, as illustrated by the lattice parameter and band gap which range from 3.807(4) [14] through 3.89Å [15] and 0.25 to 1.9 eV [16], respectively. Such variability is thought to result from differences in nitrogen content, which may vary at growth time due to nitrogen liberation [16] and is implicated in affecting the stoichiometry [17], band gap [18], native acceptor concentration [19], conductivity [20], preferential orientation [17] and decomposition temperature [16]. Stoichiometric, copper-, or nitrogen-rich films may all be prepared, with excess copper or nitrogen atoms likely incorporated in the body-center position or at grain boundaries [15,21].…”

Section: Introductionmentioning

confidence: 99%

Atypically small temperature-dependence of the direct band gap in the metastable semiconductor copper nitrideCu3N

et al. 2017

View full text Add to dashboard Cite

The temperature-dependence of the direct band gap and thermal expansion in the metastable anti-ReO 3 semiconductor Cu 3 N are investigated between 4.2 and 300 K by Fourier-transform infrared spectroscopy and x-ray diffraction. Complementary refractive index spectra are determined by spectroscopic ellipsometry at 300 K. A direct gap of 1.68 eV is associated with the absorption onset at 300 K, which strengthens continuously and reaches a magnitude of 3.5×10 5 cm −1 at 2.7 eV, suggesting potential for photovoltaic applications. Notably, the direct gap redshifts by just 24 meV between 4.2 and 300 K, giving an atypically small band-gap temperature coefficient dE g /dT of −0.082 meV/K. Additionally, the band structure, dielectric function, phonon dispersion, linear expansion, and heat capacity are calculated using density functional theory; remarkable similarities between the experimental and calculated refractive index spectra support the accuracy of these calculations, which indicate beneficially low hole effective masses and potential negative thermal expansion below 50 K. To assess the lattice expansion contribution to the band-gap temperature-dependence, a quasiharmonic model fit to the observed lattice contraction finds a monotonically decreasing linear expansion (descending past 10 −6 K −1 below 80 K), while estimating the Debye temperature, lattice heat capacity, and Grüneisen parameter. Accounting for lattice and electron-phonon contributions to the observed band-gap evolution suggests average phonon energies that are qualitatively consistent with predicted maxima in the phonon density of states. As band-edge temperature-dependence has significant consequences for device performance, copper nitride should be well suited for applications that require a largely temperature-invariant band gap.

show abstract

Fabrication and optical constants of amorphous copper nitride thin films prepared by ion beam assisted dc magnetron reactive sputtering

Cited by 27 publications

References 22 publications

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

Observation of the Direct Energy Band Gaps of Defect-Tolerant Cu₃N by Ultrafast Pump-Probe Spectroscopy

Atypically small temperature-dependence of the direct band gap in the metastable semiconductor copper nitrideCu3N

Contact Info

Product

Resources

About

Fabrication and optical constants of amorphous copper nitride thin films prepared by ion beam assisted dc magnetron reactive sputtering

Cited by 27 publications

References 22 publications

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y2O3) Ceramic in Cubic Phase

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y2O3) Ceramic in Cubic Phase

Observation of the Direct Energy Band Gaps of Defect-Tolerant Cu3N by Ultrafast Pump-Probe Spectroscopy

Atypically small temperature-dependence of the direct band gap in the metastable semiconductor copper nitrideCu3N

Contact Info

Product

Resources

About

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

First‐Principles Study of Elastic, Structural, Electronic, Thermodynamical, and Optical Properties of Yttria (Y₂O₃) Ceramic in Cubic Phase

Observation of the Direct Energy Band Gaps of Defect-Tolerant Cu₃N by Ultrafast Pump-Probe Spectroscopy