Effects of strain on electronic and optical properties of LiNbO<sub>3</sub>: a first principles study

Husin, R; Badrudin, F. W.; Taib, Mohamad Fariz Mohamad; Yahya, Muhd Zu Azhan

doi:10.1088/2053-1591/ab2a24

Cited by 10 publications

(12 citation statements)

References 55 publications

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“…The total DOS [Fig. 4(d)] that determines the band structure of the material is therefore defined by the Nb-O bonds, in agreement with previous works [20,21]. The orbitals of these bonds form the smallest at 140 • and 220 • , respectively.…”

Section: Density Of Statessupporting

confidence: 84%

Laser polarization dependence of strong-field ionization in lithium niobate

et al. 2020

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Laser micromachining techniques using femtosecond laser pulses are employed for the fabrication of a wide range of devices, from optical waveguides and fiber Bragg gratings to microfluidic systems. In this perspective, it is important to characterize how transparent materials respond to the high-intensity laser field in order to fully understand and control the strong-field ionization process at the core of such techniques. Here, we characterize the laser polarization dependence of y-cut and x-cut ferroelectric lithium niobate (LiNbO 3 ) upon ionization. Using linearly polarized 1800-nm femtosecond pulses, we perform single-shot laser-induced ablation measurements to obtain a macroscopic observable with a large contrast compared to all-optical techniques. In the tunnel ionization regime, the crystal orientation can be correlated with the structural symmetry/asymmetry of the material. This is revealed through a variation of the ablated area when the laser polarization is rotated with respect to the c axis of the crystal. It is further found that ablation is more pronounced when the laser polarization is oriented towards angular regions containing Nb-O bonds of the unit cell, identifying the main chemical bonds contributing to the ionization of the material. The experimental results are supported by numerical simulations based on a two-band model for LiNbO 3 .

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Section: Density Of Statessupporting

confidence: 84%

Laser polarization dependence of strong-field ionization in lithium niobate

et al. 2020

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“…This simpler approach, unlike the more complex BSE formalism, allows a direct comparison between one-particle levels (bands) and absorption energies. In this way, we find that the relatively broad defect peak is a superposition of transitions from the single defect level (initial state) into the lowest few conduction bands, namely, Nb 4d states [68,69] centered around 0.2 eV above the conductionband edge. This means that the bipolaron, once excited, is destroyed, and one of the excess electrons is no longer localized at the two involved central Nb atoms but delocalized over several Nb atoms.…”

Section: Modelmentioning

confidence: 84%

Free and defect-bound (bi)polarons inLiNbO3: Atomic structure and spectroscopic signatures fromab initiocalculations

Schmidt

Kozub

Biktagirov

et al. 2020

Phys. Rev. Research

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Polarons in dielectric crystals play a crucial role for applications in integrated electronics and optoelectronics. In this work, we use density-functional theory and Green's function methods to explore the microscopic structure and spectroscopic signatures of electron polarons in lithium niobate (LiNbO 3). Total-energy calculations and the comparison of calculated electron paramagnetic resonance data with available measurements reveal the formation of bound polarons at Nb Li antisite defects with a quasi-Jahn-Teller distorted, tilted configuration. The defect-formation energies further indicate that (bi)polarons may form not only at Nb Li antisites but also at structures where the antisite Nb atom moves into a neighboring empty oxygen octahedron. Based on these structure models, and on the calculated charge-transition levels and potential-energy barriers, we propose two mechanisms for the optical and thermal splitting of bipolarons, which provide a natural explanation for the reported two-path recombination of bipolarons. Optical-response calculations based on the Bethe-Salpeter equation, in combination with available experimental data and new measurements of the optical absorption spectrum, further corroborate the geometries proposed here for free and defect-bound (bi)polarons.

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“…Theoretically, many scientists studied LiNbO 3 in depth by investigating its structural, electronic, elastic, mechanical, and optical properties [16][17][18]. A few experimental works are also reported on it in [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

“…However, it is observed that electronic and optical properties are underestimated. R Husin et al [18], used to compute the electronic and optical properties of LiNbO 3 using the plane-wave pseudo-potential method along with GGA-PBEsol, LDA-CAPZ, and GGA-PBE. Authors of [18] applied GGA-PBE+Scissor operation to achieve accuracy in electronic and optical properties and still, underrated values are obtained for these properties whereas they found improvement in structural properties using PBES functional.…”

Section: Introductionmentioning

confidence: 99%

“…Hence, for the first time, we audit the response of two techniques namely, OLCAO-TB09+c and OLCAO-PBES+U on the band structure and optical properties of LiNbO 3 . Statistical analysis is done on obtained results and compared with the previously published experimental [19][20][21] as well as theoretical work [16][17][18]. MGGA-TB09 is potential only functional and hence not supported for total energy calculations.…”

Section: Introductionmentioning

confidence: 99%

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DFT based studies on the structural, electronic and optical properties of LiNbO₃ using some hybrid techniques

Kar¹,

Dharmale²,

Chaudhury³

2021

Phys. Scr.

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Structural, electronic, and optical properties of ferroelectric material, Lithium niobate (LiNbO3) are explored and studied using two different techniques namely, OLCAO-MGGA-TB09+c and OLCAO-GGA-PBES + U under the framework of density functional theory (DFT). The electronic properties such as band diagram, the effective mass of charge carriers, the total density of state (TDOS), and partial density of state (PDOS) are investigated in depth. Band gap values obtained using MGGA-TB09+c is 3.79 eV whereas, it is 3.78 eV for GGA-PBES + U. Furthermore, several optical properties such as dielectric constant, reflectivity, refractive index, optical conductivity, loss function, and absorption coefficient have also been extracted. It is seen that the results so obtained are consistent with experimental data which shows the soundness of our calculations. From the statistical analysis, it is found that both the techniques provide very good results on electronic and optical properties of LiNbO3 compared to existing computational work as both give an approximation of experimental data. The methods presented here will be useful for researchers to get accurate results on structural, electronic, and optical properties of other materials.

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Effects of strain on electronic and optical properties of LiNbO₃: a first principles study

Cited by 10 publications

References 55 publications

Laser polarization dependence of strong-field ionization in lithium niobate

Laser polarization dependence of strong-field ionization in lithium niobate

Free and defect-bound (bi)polarons inLiNbO3: Atomic structure and spectroscopic signatures fromab initiocalculations

DFT based studies on the structural, electronic and optical properties of LiNbO₃ using some hybrid techniques

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Effects of strain on electronic and optical properties of LiNbO3: a first principles study

Cited by 10 publications

References 55 publications

Laser polarization dependence of strong-field ionization in lithium niobate

Laser polarization dependence of strong-field ionization in lithium niobate

Free and defect-bound (bi)polarons inLiNbO3: Atomic structure and spectroscopic signatures fromab initiocalculations

DFT based studies on the structural, electronic and optical properties of LiNbO3 using some hybrid techniques

Contact Info

Product

Resources

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Effects of strain on electronic and optical properties of LiNbO₃: a first principles study

DFT based studies on the structural, electronic and optical properties of LiNbO₃ using some hybrid techniques