Hierarchical Architectural Structures Induce High Performance in n‐Type GeTe‐Based Thermoelectrics

Abstract

Compatible p-and n-type materials are necessary for high-performance GeTe thermoelectric modules, where the n-type counterparts are in urgent need. Here, it is reported that the p-type GeTe can be tuned into n-type by decreasing the formation energy of Te vacancies via AgBiTe 2 alloying. AgBiTe 2 alloying induces Ag 2 Te precipitates and tunes the carrier concentration close to the optimal level, leading to a high-power factor of 6.2 µW cm −1 K −2 at 423 K. Particularly, the observed hierarchical architectural structures, including phase boundaries, nano-precipitates, and point defects, contribute an ultralow lattice thermal conductivity of 0.39 W m −1 K −1 at 423 K. Correspondingly, an increased ZT of 0.5 at 423 K is observed in n-type (GeTe) 0.45 (AgBiTe 2 ) 0.55 . Furthermore, a single-leg module demonstrates a maximum η of 6.6% at the temperature range from 300 to 500 K. This study indicates that AgBiTe 2 alloying can successfully turn GeTe into n-type with simultaneously optimized thermoelectric performance.

Ultra-Low Lattice Thermal Conductivity Enables High Thermoelectric Properties in Cu and Y Codoped SnTe via Multi-Scale Composite Nanostructures

“…Notable state-of-the-art thermoelectric materials include GeTe, , Bi 2 Te 3 , PbTe, Cu 2 Se, and SnSe, among others. Although their thermoelectric properties have been significantly improved, their applications are limited by many reasons, such as toxicity, limitations on the specific orientation of single crystals, sensitivity to phase transitions, and high cost.…”

“…As can be seen, an ideal thermoelectric material possesses both large power factor (S 2 σ) and low κ lat , which depend upon transports of phonons and charge carriers, respectively. 3−10 Notable state-of-the-art thermoelectric materials include GeTe, 11,12 Bi 2 Te 3 , 13 PbTe, 14 Cu 2 Se, 15 and SnSe, 16 among others. Although their thermoelectric properties have been significantly improved, their applications are limited by many reasons, such as toxicity, limitations on the specific orientation of single crystals, sensitivity to phase transitions, and high cost.…”

Direct Current Treatment Tuning Crystallinity Leading to High-Performance p-Type Sb2Te3 Flexible Thin Films

“…Thermoelectric (TE) materials can realize direct energy conversion between electricity and heat and have demonstrated wide application potentials in the field of wearable electronics, chip sensors, and Internet of Things. − The TE power-generating performance of f-TFs can be evaluated by the power factor, S 2 σ, where S and σ are the Seebeck coefficient and electrical conductivity, respectively. , σ can be expressed as σ = n h e μ, where n h and μ represent the carrier concentration and carrier mobility, respectively, and e is the elementary charge. , Based on the Mott formula as shown in eq S1, S can be increased by reduced n h and enhanced effective mass ( m *). , However, the reduced n h also deteriorates the σ, which requires further optimization. − …”

“…8,9 Based on the Mott formula as shown in eq S1, S can be increased by reduced n h and enhanced effective mass (m*). 10,11 However, the reduced n h also deteriorates the σ, which requires further optimization. 12−14 Until now, f-TFs with high S 2 σ, including inorganic Ag 2 Se (S 2 σ ∼9.87 μW cm −1 K −2 at 300 K), 15 SWCNTs/Ag 2 Se (S 2 σ ∼19.36 μW cm −1 K −2 at 300 K), 16 SnSe (S 2 σ ∼3.5 μW cm −1 K −2 at 300 K), 17 and Bi 2 Te 3 (S 2 σ ∼14.65 μW cm −1 K −2 at 300 K) 18 and organic 3-hexylthiophene-2,5-diyl (P3HT, S 2 σ ∼0.136 μW cm −1 K −2 at 300 K), 19 polyaniline (PANI, S 2 σ ∼0.55 μW cm −1 K −2 at 300 K), 20 and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT/PSS, S 2 σ ∼0.456 μW cm −1 K −2 at 300 K), 21 have attracted extensive research interest.…”

In situ molecule-level interface tailoring of metastable intermolecular composite chips toward on-demand heat release and information encryption

“…Beneting from the merits of short mass transfer spacing and high effective area of reaction interface, a nano-sized MIC fuel possesses sufficient exothermic intensity and superior energy density, demonstrating a wide application prospect in mining, deconstruction, reworks, ordnance, electrode interfaces, medical treatments, and other elds. [5][6][7][8][9] In particular, the development of thermoelectric devices 10,11 is increasingly dependent on efficient MIC fuels. 12 Admittedly, remarkable progress has been achieved in the eld of nano-sized MIC fuels over the past decade.…”