Quantum confinement gives low-dimensional materials distinctive electronic behaviour, but assessing their effective band structure dimensionality (D) is difficult. Conventional probes such as angle-resolved photoemission spectroscopy (ARPES) or scanning tunneling microscopy (STM) demand ultra clean surfaces and expensive facilities. We introduce a generalized transport model that functions as an internal dimensionality meter: by tracking how the Seebeck coefficient varies with carrier concentration or temperature, we deduce D from two scaling laws, <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$S\propto \left(\frac{D}{2}\right){{\mathrm{ln}}}T$</EquationSource> <EquationSource Format="MATHML"><math> <mi>S</mi> <mo>∝</mo> <mfenced close=")" open="("> <mrow> <mfrac> <mrow> <mi>D</mi> </mrow> <mrow> <mn>2</mn> </mrow> </mfrac> </mrow> </mfenced> <mi mathvariant="normal">ln</mi> <mi>T</mi> </math></EquationSource> </InlineEquation> in non-degenerate regimes (e.g. <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\left|S\right|\ge 200{{{\rm{\mu }}}}{{{\rm{V}}}}{{{{\rm{K}}}}}^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mfenced close="∣" open="∣"> <mrow> <mi>S</mi> </mrow> </mfenced> <mo>≥</mo> <mn>200</mn> <mi mathvariant="normal">μ</mi> <mi mathvariant="normal">V</mi> <msup> <mrow> <mi mathvariant="normal">K</mi> </mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </math></EquationSource> </InlineEquation>) and <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$S\propto {n}^{-2/D}$</EquationSource> <EquationSource Format="MATHML"><math> <mi>S</mi> <mo>∝</mo> <msup> <mrow> <mi>n</mi> </mrow> <mrow> <mo>−</mo> <mn>2</mn> <mo>/</mo> <mi>D</mi> </mrow> </msup> </math></EquationSource> </InlineEquation> in degenerate regimes (e.g. <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$\left|S\right|\le 150\,{{{\rm{\mu }}}}{{{\rm{V}}}}{{{{\rm{K}}}}}^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mfenced close="∣" open="∣"> <mrow> <mi>S</mi> </mrow> </mfenced> <mo>≤</mo> <mn>150</mn> <mspace width="0.25em" /> <mi mathvariant="normal">μ</mi> <mi mathvariant="normal">V</mi> <msup> <mrow> <mi mathvariant="normal">K</mi> </mrow> <mrow> <mo>−</mo> <mn>1</mn> </mrow> </msup> </math></EquationSource> </InlineEquation>). Applying this approach to SrTiO3, few-layer Bi2O2Se and Pb1-xSnxTe uncovers temperature-, doping- and alloy-induced crossovers between three-dimensional and lower-dimensional transport. The method offers a rapid, scattering independent framework to design quantum and thermoelectric properties.

Dimensional transport crossovers in thermoelectrics revealed by a simple transport model

期刊论文
出版模式：

开放获取
发表日期：

2025年12月11日

查看全文

Xiaoxuan Zhang,
Thomas C. Chasapis,
Kaiqing Lu,
Maxwell Thomas Dylla,
Meizhu Huang,
G. Jeffrey Snyder,
Yue Lin

摘要

Quantum confinement gives low-dimensional materials distinctive electronic behaviour, but assessing their effective band structure dimensionality (D) is difficult. Conventional probes such as angle-resolved photoemission spectroscopy (ARPES) or scanning tunneling microscopy (STM) demand ultra clean surfaces and expensive facilities. We introduce a generalized transport model that functions as an internal dimensionality meter: by tracking how the Seebeck coefficient varies with carrier concentration or temperature, we deduce D from two scaling laws, $S\propto \left(\frac{D}{2}\right){{\mathrm{ln}}}T$ $S \propto (\frac{D}{2}) \ln T$ in non-degenerate regimes (e.g. $\left|S\right|\ge 200{{{\rm{\mu }}}}{{{\rm{V}}}}{{{{\rm{K}}}}}^{-1}$ $∣S∣ \geq 200 μ V K^{- 1}$ ) and $S\propto {n}^{-2/D}$ $S \propto n^{- 2 / D}$ in degenerate regimes (e.g. $\left|S\right|\le 150\,{{{\rm{\mu }}}}{{{\rm{V}}}}{{{{\rm{K}}}}}^{-1}$ $∣S∣ \leq 150 μ V K^{- 1}$ ). Applying this approach to SrTiO₃, few-layer Bi₂O₂Se and Pb_1-xSn_xTe uncovers temperature-, doping- and alloy-induced crossovers between three-dimensional and lower-dimensional transport. The method offers a rapid, scattering independent framework to design quantum and thermoelectric properties.