Achieving a High Average zT Value in Sb₂Te₃-Based Segmented Thermoelectric Materials

Abstract

A tiny amount of Mn is doped in In0.15Sb1.85Te3 sample to tailor its carrier concentration, thus boosting the power factor and suppressing the bipolar effect. Furthermore, large amounts of nanotwins are constructed to effectively scatter the phonons and reduce the lattice thermal conductivity. As a result, the zT value of Mn0.02In0.15Sb1.83Te3 is enhanced up to 1.0 at 673 K, making this material a robust candidate for medium-temperature (500–673 K) thermoelectric applications. Then combining with the low-temperature thermoelectric material Mn0.0075Bi0.5Sb1.4925Te3 previously reported by our group and using nickel as a barrier layer, a high average zT value of 1.08 during a broad temperature range from 303 to 673 K together with an Ohmic contact interface bonding is achieved in the p-type segmented leg fabricated via simple one-step sintering. Finally, the maximum theoretical conversion efficiency with a temperature difference of 370 K reaches ∼12.7%.

Realize High Thermoelectric Properties in n-Type Bi2Te2.7Se0.3/Y2O3 Nanocomposites by Constructing Heterointerfaces

“…At 373 K, the maximum ZT of BTS + 1.5 wt % Y 2 O 3 NC reaches 1.21, which is much higher than that of the pristine BTS (0.67). It should be noted that the ZT values of the BTS composite with 1.5 wt % Y 2 O 3 keep above unity over the entire operative temperature range, which is superior to most of the n-type Bi 2 Te 3 -based thermoelectric materials in recent years. ,− The value of ZT ave can be obtained by integrating the area under ZT curves according to the formula: …”

Simultaneously Improved Thermoelectric and Mechanical Properties Driven by MgB2 Doping in Bi0.4Sb1.6Te3 Based Alloys

“…Compared to the pristine Bi 0.4 Sb 1.6 Te 3 , the S of MgB 2 doped samples is drastically decreased. Based on the assumption of the single parabolic band (SPB) model, [ 14 ] the Pisarenko curve is calculated and plotted in Figure S1, Supporting Information. All experimental results match well with the calculated line, indicating that MgB 2 doping has almost no influence on the valence band structure.…”

Nanotwins Strengthening High Thermoelectric Performance Bismuth Antimony Telluride Alloys

“…[35] In the past decade, nanotwins have been reported in these Bi 2 Te 3 based alloys prepared by ball milling followed by hot pressing. [36][37][38][39][40] Besides, Hayashi et al also reported the occur-rence of twins in the Bi 1.9 Sb 0.1 Te 2.7 Se 0.3 prepared by equal channel angular extrusion. [41] In these works, the twins are thought to be generated from the severe deformation, similar to the deforming twins observed in face-centered cubic (FCC) crystals with nanocrystal grains.…”

“…[ 35 ] In the past decade, nanotwins have been reported in these Bi 2 Te 3 based alloys prepared by ball milling followed by hot pressing. [ 36–40 ] Besides, Hayashi et al. also reported the occurrence of twins in the Bi 1.9 Sb 0.1 Te 2.7 Se 0.3 prepared by equal channel angular extrusion.…”