Dimensional transport crossovers in thermoelectrics revealed by a simple transport model.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41381427.
- Also identified by DOI 10.1038/s41467-025-65985-5 and PMC identifier 12698694.
- Licence recorded as CC BY-NC-ND.
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Abstract
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, <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>S</mi> <mo>∝</mo> <mfenced> <mrow> <mfrac><mrow><mi>D</mi></mrow> <mrow><mn>2</mn></mrow> </mfrac> </mrow> </mfenced> <mi>ln</mi> <mi>T</mi></math> in non-degenerate regimes (e.g. <math xmlns="http://www.w3.org/1998/Math/MathML"> <mfenced><mrow><mi>S</mi></mrow> </mfenced> <mo>≥</mo> <mn>200</mn> <mi>μ</mi> <mi>V</mi> <msup><mrow><mi>K</mi></mrow> <mrow><mo>-</mo> <mn>1</mn></mrow> </msup> </math> ) and <math xmlns="http://www.w3.org/1998/Math/MathML"><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> in degenerate regimes (e.g. <math xmlns="http://www.w3.org/1998/Math/MathML"> <mfenced><mrow><mi>S</mi></mrow> </mfenced> <mo>≤</mo> <mn>150</mn> <mspace></mspace> <mi>μ</mi> <mi>V</mi> <msup><mrow><mi>K</mi></mrow> <mrow><mo>-</mo> <mn>1</mn></mrow> </msup> </math> ). Applying this approach to SrTiO<sub>3</sub>, few-layer Bi<sub>2</sub>O<sub>2</sub>Se and Pb<sub>1-x</sub>Sn<sub>x</sub>Te 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.