Study of photoluminescence in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cu</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>O

Pétroff, Y.; Yu, P.Y.; Shen, Yuzhen

doi:10.1103/physrevb.12.2488

Cited by 105 publications

(54 citation statements)

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“…The unusual peak shape is due to the convolution of the orthoexciton peak and the phononassisted exciton peak, which broadens and grows at higher temperatures where the absorption probability of phonons by excitons is large. 5,[21][22] The peak was evident even at the lowest of excitation powers (0.85 µW). Thus, excitons are generated under visible excitation even in polycrystalline Cu 2 O substrates used in photovoltaic fabrication.…”

Section: S6 Characteristics Of Polycrystalline Cu 2 O Wafersmentioning

confidence: 95%

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O

et al. 2017

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Excitonic effects account for a fundamental photoconversion and charge transport mechanism in Cu2O; hence, the universally adopted “free carrier” model substantially underestimates the photovoltaic efficiency for such devices. The quasi-equilibrium branching ratio between excitons and free carriers in Cu2O indicates that up to 28% of photogenerated carriers during photovoltaic operation are excitons. These large exciton densities were directly observed in photoluminescence and spectral response measurements. The results of a device physics simulation using a model that includes excitonic effects agree well with experimentally measured current–voltage characteristics of Cu2O-based photovoltaics. In the case of Cu2O, the free carrier model underestimates the efficiency of a Cu2O solar cell by as much as 1.9 absolute percent at room temperature.

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Section: S6 Characteristics Of Polycrystalline Cu 2 O Wafersmentioning

confidence: 95%

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O

et al. 2017

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“…Extensive experimental data including specific heat measurements [23,24], Raman and IR detection of long-wavelength optically active phonons [25,26] together with neutron derived phonon dispersion relations and phonon density of states [27,28] have been reported for Cu 2 O while the calculations of the volume thermal expansion in Ag 2 O and Cu 2 O have also been published [15,16,28]. EXAFS measurements on Ag 2 O and Cu 2 O [19][20][21][22] indicate that the mechanism at the origin of their NTE involves deformations of the M 4 O tetrahedral units (M = Ag, Cu), rather than simple rigid units vibrations.…”

Section: Introductionmentioning

confidence: 99%

Phonons, nature of bonding, and their relation to anomalous thermal expansion behavior of M2O (M = Au, Ag, Cu)

Gupta

Chaplot

Rols

2014

Journal of Applied Physics

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“…We have to mention that in photoluminescence studies a very sharp but weak exciton peak associated with the 1s exciton is observed in Cu 2 O at 2.033 eV. The corresponding radiative electron-hole-pair recombination is due to magnetic-dipole and electric-quadrupole Γ + 7v → Γ + 6c transitions [40]. Identifying the ionization edge with E g = 2.166 eV [38], one obtains a binding energy of 133 meV for the 1s state.…”

Section: Allowed and Forbidden Optical Transitionsmentioning

confidence: 97%

Excitons

Bechstedt¹

2014

Springer Series in Solid-State Sciences

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The general procedure to account for many-body effects in optical and energy-loss spectra consists of three steps, (i) preparation of a starting electronic structure, (ii) its improvement due to quasiparticle effects, and (iii) the inclusion of electron-hole attraction and exchange. Their combination gives rise to novel quasiparticles, the excitons. Singlet and triplet states differ by twice the electron-hole exchange. Instructive exciton models are derived studying only pairs of conduction and valence bands. For large distances of electron and hole in real space the effective mass approximation and a constant screening can be employed. The resulting pairs are hydrogen-like Wannier-Mott excitons, which give rise to Rydberg series below the ionization edge and a Coulomb enhancement, the Sommerfeld factor, of the pair density of states above the edge. Localized excitons such as Frenkel and charge-transfer excitons possess larger binding energies and electron-hole distances of the order of atomic or molecular distances. Exciton binding is increased by spatial confinement as demonstrated for two-dimensional systems. Electron-Hole Pairs: Top-Down Approach TerminologyIn the previous Chaps. 18-20 we have described in detail the response of an electronic system to an external perturbation, which however leaves this system neutral. Especially perturbations which are related to the real or virtual absorption of photons with energy ω or the inelastic scattering of high-energy particles with energy losses of energy ω have been considered as examples. Thereby we have learnt that the many-electron interactions mediated by the Coulomb potential play a central role. We found that the treatment of their influence can be nearly divided into a three-step procedure that is schematically illustrated in Fig. 21.1 for a non-metal. In a first step an electron-hole pair may be actually or virtually excited by a photon of energy ω in the reference electronic structure derived from a Kohn-Sham or generalized Kohn-Sham problem. In the second step the formation of quasiparticles is taken into account. As a consequence an energy shift of the bands is considered resulting in an

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Study of photoluminescence inCu2O

Cited by 105 publications

References 20 publications

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O

Phonons, nature of bonding, and their relation to anomalous thermal expansion behavior of M2O (M = Au, Ag, Cu)

Excitons

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Study of photoluminescence inCu2O

Cited by 105 publications

References 20 publications

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu2O

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu2O

Phonons, nature of bonding, and their relation to anomalous thermal expansion behavior of M2O (M = Au, Ag, Cu)

Excitons

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Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O

Excitonic Effects in Emerging Photovoltaic Materials: A Case Study in Cu₂O