Influence of GeP precipitates on the thermoelectric properties of P-type GeTe and Ge0.9−xPxSb0.1Te compounds

Gandhi, J. Rajeev; Nehru, Raja; Bayikadi, Khasim Saheb; Sureshkumar, P.; Chen, Kuei‐Hsien; Chen, Li‐Chyong

doi:10.1039/c8ce01134f

Cited by 9 publications

(1 citation statement)

References 35 publications

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“…When the interaxial angle α changes from 88.2 to 90°, it enables the convergence of the original 3 L + 1 Z in the cubic structure into 4 L , and 6∑ + 6η into 12∑, which provides a potential degree of freedom for GeTe performance optimization . The nonstoichiometric equilibrium of the pristine GeTe is derived from the extremely low Ge-vacancy formation energy, , and the detectable Ge-rich phase and high carrier concentration ∼10 21 cm –3 result in high thermal conductivity and low Seebeck coefficient . The thermoelectric performance for the pristine GeTe is limited by the non-negligible drawbacks.…”

Section: Introductionmentioning

confidence: 99%

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys

Tan

Zhang

Zhu

et al. 2023

ACS Appl. Mater. Interfaces

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The emerged strategy of manipulating the rhombohedral crystal structure provides another new degree of freedom for optimizing the thermoelectric properties of GeTe-based compounds. However, the concept is difficult to be effectively measured and often depends on heavy doping that scatters carriers severely. Herein, we synergistically manipulate lattice distortion and vacancy concentration to promote the excellent electrical transport of GeTe-Cu2Te alloys and quantify the interaxial angle-dependent density of state effective mass. Distinct from the conventional electronic coupling effect, about 2% substitution of Zr4+ significantly increases the interaxial angle, thereby enhancing the band convergence effect and improving the Seebeck coefficient. In addition, Ge-compensation attenuates the mobility deterioration, leading to improved power factor over the whole temperature range, especially exceeding ∼22 μW cm–1 K–2 at 300 K. Furthermore, the Debye–Callaway model elucidates low lattice thermal conductivity due to strong phonon scattering from Zr/Ge substitutional defects. As a result, the highest figure of merit zT of ∼1.6 (at 650 K) and average zT ave of ∼0.9 (300–750 K) are obtained in (Ge1.01Zr0.02Te)0.985(Cu2Te)0.015. This work demonstrates the effective band modulation of Zr on GeTe-based materials, indicating that the modification of the interaxial angle is a deep pathway to improve thermoelectrics.

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Section: Introductionmentioning

confidence: 99%

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys

Tan

Zhang

Zhu

et al. 2023

ACS Appl. Mater. Interfaces

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Trends in GeTe Thermoelectrics: From Fundamentals to Applications

Li,

Shi,

Chen

2024

Adv Funct Materials

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Germanium telluride (GeTe) with ultrafast ferroelectric transition, Rashba‐like electronic transport, and anomalous phonon anharmonicity are historically studied for potential memorizing and thermoelectric applications. Due to recent breakthroughs in spintronics, valleytronics, orbitronics, pre‐eminent GeTe thermoelectrics have re‐attracted enormous interest from both academia and industries, with increasing reports of significant figure‐of‐merit over 2.7 and the maximum efficiency of up to 17.0%. Here, the emerging trends in advancing GeTe thermoelectrics, starting from fundamentals of phase transformation, crystal structure, bonding mechanisms, and transport characteristics, with a highlight on the roles of Ge_4s2 lone pairs, are timely overviewed. Technical insights in synthesis, characterization, property measurement, and computation are then summarized. After that, several innovative strategies for increasing the figure‐of‐merit, including entropy engineering, nanostructuring, and hybridization, which will further benefit near‐room‐temperature and n‐type performance, are examined. Moreover, high‐density and high‐efficiency devices with broad working temperatures are discussed as a result of rational configurational and interfacial design. In the end, perspective remarks on the challenges and outlook envisaging for next‐generation GeTe thermoelectrics, which will play a prominent role in future energy and environmental landscapes, are provided.

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High wide-temperature-range thermoelectric performance in GeTe through hetero-nanostructuring

Zhang,

Ying,

Farrukh

et al. 2024

Acta Materialia

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Influence of GeP precipitates on the thermoelectric properties of P-type GeTe and Ge_0.9−xP_xSb_0.1Te compounds

Abstract: The incorporation of P in GST forms the secondary GeP rich phase. The presence of secondary phase and point defects (Sb and P) enhanced the additional scattering effects in the system.

Cited by 9 publications

References 35 publications

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys

Trends in GeTe Thermoelectrics: From Fundamentals to Applications

High wide-temperature-range thermoelectric performance in GeTe through hetero-nanostructuring

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Influence of GeP precipitates on the thermoelectric properties of P-type GeTe and Ge0.9−xPxSb0.1Te compounds

Abstract: The incorporation of P in GST forms the secondary GeP rich phase. The presence of secondary phase and point defects (Sb and P) enhanced the additional scattering effects in the system.

Cited by 9 publications

References 35 publications

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu2Te Alloys

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu2Te Alloys

Trends in GeTe Thermoelectrics: From Fundamentals to Applications

High wide-temperature-range thermoelectric performance in GeTe through hetero-nanostructuring

Contact Info

Product

Resources

About

Influence of GeP precipitates on the thermoelectric properties of P-type GeTe and Ge_0.9−xP_xSb_0.1Te compounds

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys

High-Power Factor Enabled by Efficient Manipulation Interaxial Angle for Enhancing Thermoelectrics of GeTe-Cu₂Te Alloys