Enhanced thermoelectric performance of GeTe-rich germanium antimony tellurides through the control of composition and structure

Abstract

Enhancement of the thermoelectric performance of GeTe-rich germanium antimony telluride (GeSbTe or GST) is demonstrated through marginal changes in composition and subsequent quenching of crystal structure.

High Thermoelectric Performance and Enhanced Mechanical Stability of p-type Ge1–xSbxTe

“…38 Although Pb-free thermoelectric is desirable for mass-market applications, high performance Ge x Pb 1-x Te composition contains 13 mol% of Pb. Mention must be made that homologous (GeTe) n Sb 2 T 3 (GST) based layered compounds (without any second phase nanostructuring) are known to show zT of 1.3-1.4 at around 723 K. [39][40][41][42] Here we report an extraordinary thermoelectric performance in p-type Ge 1-x Sb x Te high quality crystalline ingots with a thermoelectric figure of merit, zT, of ~1.85 at 725 K.…”

Argyrodite‐Type Cu8GeSe6–xTex (0 ≤ x ≤ 2): Temperature‐Dependent Crystal Structure and Thermoelectric Properties

“…Germanium antimony tellurides (GeTe) n Sb 2 Te 3 (GST materials) are known as thermoelectric materials with high figures of merit . Partial substitution of Te against Se improves the thermoelectric properties, e.g.…”

Cobalt germanide precipitates indirectly improve the properties of thermoelectric germanium antimony tellurides

“…The cobalt germanide precipitates may also contain very small amounts of Te, which most likely has no pronounced effect on their weight fraction. As GST materials exhibit a certain homogeneity range, 36 this deviation is negligible as no other types of precipitates were detected. In the following sections, all heterostructured samples are represented by their formal nominal compositions in order to avoid the repetition of this discussion.…”

“…34 Instead of nano-and micro-inclusions of second phase, pronounced real structure effects in chemically homogeneous GST materials are also beneficial concerning their thermoelectric properties. 6,[35][36][37][38][39] Compounds (GeTe) n Sb 2 Te 3 with n Z 3 exhibit a disordered rocksalt-type high-temperature modification. Quenching this phase affords a metastable pseudocubic modification with short-range vacancy ordering and herringbone-like twinned nanostructures.…”