Photoluminescence spectra and biaxial stress effects of yellow 1S excitons in Cu2O thin films recrystallized epitaxially between paired MgO plates

Aihara, Shingo; Ota, Akinobu; Iwamitsu, Kazunori; Ichikawa, Fusao; Isobe, Hiroshi; Shimamoto, Tadashi; Akai, Ichiro

doi:10.1016/j.jlumin.2015.06.031

Cited by 2 publications

(10 citation statements)

References 13 publications

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“…These

σ_{〈 \hat{Θ} 〉}

are sufficiently small, and it is guaranteed that the spectral parameters other than the PL intensities have no polarization dependence. In addition, a phonon energy providing the phonon sideband PL was also estimated to be

14.12 \pm 0.04 m e V

from the energy difference between

{true \overset{E}{true}}_{G n}

and

{true \overset{E}{true}}_{M B n}

(

n = 1, 2

), and it is consistent with the previous results …”

Section: Discussionsupporting

confidence: 90%

“…14 meV, where this value is identical with the energy of

{normalΓ}_{12}^{-}

phonon in Cu 2 O . Therefore, one can conclude that the G1 and G2 are resonant PL bands due to doubly‐split 1S yellow ortho‐exciton states, and the MB1 and MB2 are their phonon sideband PL by the

{normalΓ}_{12}^{-}

phonon . At this moment, the origin of G3 band is unknown.…”

Section: Resultsmentioning

confidence: 75%

“…The resonant PL due to the ortho‐exciton states brings about by quadrupole transitions . The quadrupole‐transition operator can be expressed as

x y \sin ϕ \sin θ + y z \cos ϕ \sin θ + z x \cos θ

by using radial characteristics ( xy , yz , and zx ) and angles

ϕ

and

θ

, where the

ϕ

and

θ

are depicted in Table (c), and specify the propagating direction and polarization angles of PL photons, respectively.…”

Section: Discussionmentioning

confidence: 99%

“…On the other hand, we have prepared Cu 2 O thin‐crystals recrystallized epitaxially in a small gap between paired MgO substrates . In such thin‐crystals, we have considered that both sample‐thinning and formation of exciton‐trapping potential can be achieved at the same time.…”

Section: Introductionmentioning

confidence: 99%

“…Because a lattice constant of Cu 2 O (=4.27 Å) is slightly larger than that of MgO (=4.216 Å) at room temperature, we can expect that a planar‐biaxial compressive stress applies to the Cu 2 O unit cell as drawn by thick gray arrows in Figure . In our previous work on the Cu 2 O thin‐crystal, we took polarizing microscope images and measured complicated photoluminescence (PL) spectra of the 1S yellow ortho‐excitons. However, it is difficult to analyze the biaxial stress effect in the Cu 2 O thin‐crystals because the measured PL spectra complexly consist of weak resonant and intense phonon sideband PL bands due to doubly‐ or triply‐split 1S yellow ortho‐exciton states.…”

Section: Introductionmentioning

confidence: 99%

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Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Kiridoshi

Aihara

Arishima

et al. 2018

Physica Status Solidi (b)

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By using Bayesian spectroscopy, we studied polarization dependence of photoluminescence (PL) spectra in doubly‐split 1S yellow ortho‐excitons in a Cu2O thin‐crystal recrystallized in a small gap between paired MgO substrates. In these thin‐crystals, biaxial stresses are expected to be involved due to a small lattice mismatch between Cu2O and MgO. Under a planar‐isotropic biaxial stress, the cubic symmetry degrades to the tetragonal one in Cu2O, and subsequently, the ortho‐exciton state splits into two states having different symmetries. Consequently, the resonant PL intensities of the doubly‐split ortho‐excitons are expected to show different polarization dependencies. To elucidate such biaxial stress effect, we measured polarization dependence of the PL spectra at 4.2 K. Although resonant weak PL bands of the doubly‐split exciton states and their intense phonon sidebands co‐exist, we succeeded in decomposing to the respective spectral components by the Bayesian spectroscopy with a replica exchange Monte Carlo algorithm. As a result, it is found that the resonant PL band appearing on higher energy side shows hardly polarization dependence, whereas the resonant PL band appearing on lower energy side is further weak and shows noticeable polarization dependence. These results can be explained by the selection rule and polarization dependences on the transition matrix elements of quadrupole transitions of the doubly‐split ortho‐exciton states, and it clearly shows that the crystal symmetry degrades to D4h by the isotropic biaxial stress involved in the Cu2O thin‐crystals.

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“…These

σ_{〈 \hat{Θ} 〉}

14.12 \pm 0.04 m e V

from the energy difference between

{true \overset{E}{true}}_{G n}

and

{true \overset{E}{true}}_{M B n}

(

n = 1, 2

), and it is consistent with the previous results …”

Section: Discussionsupporting

confidence: 90%

“…14 meV, where this value is identical with the energy of

{normalΓ}_{12}^{-}

phonon in Cu 2 O . Therefore, one can conclude that the G1 and G2 are resonant PL bands due to doubly‐split 1S yellow ortho‐exciton states, and the MB1 and MB2 are their phonon sideband PL by the

{normalΓ}_{12}^{-}

phonon . At this moment, the origin of G3 band is unknown.…”

Section: Resultsmentioning

confidence: 75%

“…The resonant PL due to the ortho‐exciton states brings about by quadrupole transitions . The quadrupole‐transition operator can be expressed as

x y \sin ϕ \sin θ + y z \cos ϕ \sin θ + z x \cos θ

by using radial characteristics ( xy , yz , and zx ) and angles

ϕ

and

θ

, where the

ϕ

and

θ

are depicted in Table (c), and specify the propagating direction and polarization angles of PL photons, respectively.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Kiridoshi

Aihara

Arishima

et al. 2018

Physica Status Solidi (b)

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Strained lateral structure and its relaxation in a Cu₂O thin crystal epitaxially grown on MgO surface

Yakura

Iwamitsu

Hira

et al. 2020

Jpn. J. Appl. Phys.

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We measured in-plane X-ray diffraction and investigated the strained lateral structure and its relaxation in a Cu2O thin crystal epitaxially grown in a small gap between paired MgO substrates. Although one side MgO was peeled off to irradiate Cu2O with X-ray, a thin MgO layer remained on Cu2O, and diffraction peaks of (400)-planes in both MgO and Cu2O were detected. The peak has four-fold symmetry on sample rotation, and the lattice constant estimated from the diffraction angle is 4.254 Å. The lattice constant is larger than that of MgO and smaller than that of strain-free Cu2O. Furthermore, it was found that the lattice strain in Cu2O relaxes at a depth of ≈0.15 μm from MgO on the basis of the estimated X-ray penetration depth under consideration of low incident angle, absorption and refraction of X-ray.

show abstract

Photoluminescence spectra and biaxial stress effects of yellow 1S excitons in Cu2O thin films recrystallized epitaxially between paired MgO plates

Cited by 2 publications

References 13 publications

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Strained lateral structure and its relaxation in a Cu₂O thin crystal epitaxially grown on MgO surface

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Photoluminescence spectra and biaxial stress effects of yellow 1S excitons in Cu2O thin films recrystallized epitaxially between paired MgO plates

Cited by 2 publications

References 13 publications

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu2O Thin‐Crystal Sandwiched by MgO Substrates

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu2O Thin‐Crystal Sandwiched by MgO Substrates

Strained lateral structure and its relaxation in a Cu2O thin crystal epitaxially grown on MgO surface

Contact Info

Product

Resources

About

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Bayesian Spectroscopy on Polarization Dependent Photoluminescence Spectra of Doubly‐Split Excitons in a Cu₂O Thin‐Crystal Sandwiched by MgO Substrates

Strained lateral structure and its relaxation in a Cu₂O thin crystal epitaxially grown on MgO surface