The structural, optoelectronic, and magnetic properties of LiXO2 (X = Co, Ni) delafossite compounds are evaluated using first-principles based DFT calculations to investigate their potential applications in optoelectronic and spintronic devices. Based on calculated ground state energies, LiNiO2 is a more stable compound, compared to LiCoO2. The indirect energy band gap for LiCoO2 and LiNiO2 are 4.95 and 5.02 eV, respectively, in spin (↑) direction. However, in spin (↓) direction, the values of energy band gaps are 2.05 and 1.82 eV for LiCoO2 and LiNiO2, respectively. The total magnetic moment <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${m}_{tot}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>m</mi> <mrow> <mi mathvariant="italic">tot</mi> </mrow> </msub> </math></EquationSource> </InlineEquation> values for LiCoO2 are higher, compared to LiNiO2. Unfilled d-orbitals (Co <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq2.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">$-{3d}^{7}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>-</mo> <msup> <mrow> <mn>3</mn> <mi>d</mi> </mrow> <mn>7</mn> </msup> </mrow> </math></EquationSource> </InlineEquation> and Ni <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq3.gif" Format="GIF" Height="18" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">$-{3d}^{8}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>-</mo> <msup> <mrow> <mn>3</mn> <mi>d</mi> </mrow> <mn>8</mn> </msup> </mrow> </math></EquationSource> </InlineEquation>) in transition metals are responsible for highest portion of <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq1.gif" Format="GIF" Height="12" Rendition="HTML" Resolution="72" Type="Linedraw" Width="32" /> </InlineMediaObject> <EquationSource Format="TEX">${m}_{tot}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>m</mi> <mrow> <mi mathvariant="italic">tot</mi> </mrow> </msub> </math></EquationSource> </InlineEquation>. Based on <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq5.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="35" /> </InlineMediaObject> <EquationSource Format="TEX">$n(\omega )$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>n</mi> <mo stretchy="false">(</mo> <mi>ω</mi> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation> values of LiXO2 (X = Co, Ni) delafossite compounds, we can infer that these compounds are optically active materials, as their values are between 1.0 and 2.0. The <InlineEquation ID="IEq6"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="13538_2025_1815_Article_IEq6.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="39" /> </InlineMediaObject> <EquationSource Format="TEX">${\varepsilon }_{2}(\omega )$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>ε</mi> <mn>2</mn> </msub> <mrow> <mo stretchy="false">(</mo> <mi>ω</mi> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> spectra demonstrate that LiXO2 (X = Co, Ni) compounds are auspicious entrants for solar cell appliances working in visible and UV regions. It can be inferred from the computed results that these crystalline materials are promising candidates for prospective photovoltaic appliances.

Quantum-Engineered LiXO₂ (X = Co, Ni) Delafossites: First-Principles Design of Structural, Optoelectronic, Thermodynamic, and Magnetic Frameworks for Next-Generation Energy Harvesting

期刊论文
发表日期：

2025年6月10日

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Zeesham Abbas,
Samah Al-Qaisi,
Afaf Khadr Alqorashi,
Khalida Bibi,
Mohd Taukeer Khan,
Amna Parveen

摘要

The structural, optoelectronic, and magnetic properties of LiXO₂ (X = Co, Ni) delafossite compounds are evaluated using first-principles based DFT calculations to investigate their potential applications in optoelectronic and spintronic devices. Based on calculated ground state energies, LiNiO₂ is a more stable compound, compared to LiCoO₂. The indirect energy band gap for LiCoO₂ and LiNiO₂ are 4.95 and 5.02 eV, respectively, in spin (↑) direction. However, in spin (↓) direction, the values of energy band gaps are 2.05 and 1.82 eV for LiCoO₂ and LiNiO₂, respectively. The total magnetic moment ${m}_{tot}$ $m_{tot}$ values for LiCoO₂ are higher, compared to LiNiO₂. Unfilled d-orbitals (Co $-{3d}^{7}$ $- {3 d}^{7}$ and Ni $-{3d}^{8}$ $- {3 d}^{8}$ ) in transition metals are responsible for highest portion of ${m}_{tot}$ $m_{tot}$ . Based on $n(\omega )$ $n (ω)$ values of LiXO₂ (X = Co, Ni) delafossite compounds, we can infer that these compounds are optically active materials, as their values are between 1.0 and 2.0. The ${\varepsilon }_{2}(\omega )$ $ε_{2} (ω)$ spectra demonstrate that LiXO₂ (X = Co, Ni) compounds are auspicious entrants for solar cell appliances working in visible and UV regions. It can be inferred from the computed results that these crystalline materials are promising candidates for prospective photovoltaic appliances.