Structural, elastic and thermodynamic properties of anti-ReO3 type Cu3N under pressure from first principles

Kong, Fanjie; Hu, Yanfei; Wang, Yanzong; Wang, Baolin; Tang, Lin

doi:10.1016/j.commatsci.2012.07.025

Cited by 14 publications

(10 citation statements)

References 38 publications

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“…The CB minimum is dominated by p orbitals with 65% contribution and d orbitals with 35% contribution of Cu atoms. These findings are in good agreement with electronic band structure calculations carried out previously on Cu 3 N. ,− …”

Section: Resultssupporting

confidence: 92%

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

et al. 2020

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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.

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Section: Resultssupporting

confidence: 92%

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

et al. 2020

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“…The deviation from the linear trend takes place at the pressure of 10 GPa which could be related to an electronic type of phase transition. The results are close to that reported by Kong et al [19].…”

Section: Structural and Elastic Propertiessupporting

confidence: 92%

“…The calculated sound velocity and Debye temperature as well as the density for Cu 3 N are given in table 2. The obtained values are in good agreement with other reports [19]. Figure 4 shows that the structure maintains the mechanical stability conditions over the applied pressure and does not undergo any structural phase transition, while experimental results show a phase transition above 5 GPa applied pressure [20].…”

Section: Structural and Elastic Propertiessupporting

confidence: 90%

The effect of pressure on the physical properties of Cu₃N

Ghoohestani¹,

Karimipour²,

Javdani³

2014

Phys. Scr.

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The structural, optical and electronic properties of the copper nitride (Cu 3 N) bulk structure under pressure have been studied by performing accurate total energy calculations in the framework of density functional theory using the full-potential linearized augmented plane wave method. Perdew-Burke-Ernzerhof and modified Becke-Johnson parameterizations of the generalized gradient approximation were employed to obtain the structural and electronic properties of Cu 3 N. The most stable crystal structure of the Cu 3 N compound was found to be cubic anti-ReO 3 at ambient pressure. Moreover, the calculation of the enthalpy of different crystal structures of Cu 3 N for different pressures indicates that the anti-ReO 3 cubic phase undergoes a structural phase transition for pressures higher than 30 GPa. The study of the elastic constants of the anti-ReO 3 cubic phase confirms that Cu 3 N is mechanically stable under hydrostatic pressures up to 30 GPa. Moreover, with the application of pressure, the C 44 elastic constant, shear module and Debye temperature deviate from linear behavior at 10 GPa. An electronic study shows that there is an electronic-type phase transition from semiconductor to metal between 5 and 10 GPa and metal to semi-metal between 20 and 30 GPa applied pressures. Cu 3 N is an indirect band gap semiconductor with a value of 0.56 eV.

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“…Much of the previous DFT work on Cu 3 N uses functionals likely to inaccurately determine the band gap [64][65][66]. Evaluation of the HSE06 band structure along a reciprocal space path tracing all edges of the irreducible primitive cubic Brillouin zone [67] [see Fig.…”

Section: Theoretical Studiesmentioning

confidence: 99%

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

et al. 2017

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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.

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Structural, elastic and thermodynamic properties of anti-ReO3 type Cu3N under pressure from first principles

Cited by 14 publications

References 38 publications

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

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

The effect of pressure on the physical properties of Cu₃N

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

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Structural, elastic and thermodynamic properties of anti-ReO3 type Cu3N under pressure from first principles

Cited by 14 publications

References 38 publications

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

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

The effect of pressure on the physical properties of Cu3N

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

Contact Info

Product

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

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

The effect of pressure on the physical properties of Cu₃N