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Realizing high average thermoelectric figure of merit (ZTave) and power factor (PFave) has been the utmost task in thermoelectrics. Here the new strategy to independently improve constituent factors in ZT is reported, giving exceptionally high ZTave and PFave in n‐type PbSe. The nonstoichiometric, alloyed composition and resulting defect structures in new Pb1+xSe0.8Te0.2 (x = 0–0.125) system is key to this achievement. First, incorporating excess Pb unusually increases carrier mobility (µH) and concentration (nH) simultaneously in contrast to the general physics rule, thereby raising electrical conductivity (σ). Second, modifying charge scattering mechanism by the authors' synthesis process boosts a magnitude of Seebeck coefficient (S) above theoretical expectations. Detouring the innate inverse proportionality between nH and µH; and σ and S enables independent control over them and change the typical trend of PF to temperature, giving remarkably high PFave ≈20 µW cm−1 K−2 from 300 to 823 K. The dual incorporation of Te and excess Pb generates unusual antisite Pb at the anionic site and displaced Pb from the ideal position, consequently suppressing lattice thermal conductivity. The best composition exhibits a ZTave of ≈1.2 from 400 to 823 K, one of the highest reported for all n‐type PbQ (Q = chalcogens) materials. [ABSTRACT FROM AUTHOR]

Thermoelectric materials can directly convert heat to electricity and vice versa. ZT (= S 2 σ T / κ) is usually used for evaluating the performance of thermoelectric materials. Improving ZT is a challenging task because of the strong interdependence among the Seebeck coefficient (S), electrical conductivity (σ) and thermal conductivity (κ). This review provides a summary of some promising thermoelectric materials in different developing stages with emphasis on the corresponding strategies for thermoelectric performance enhancement. In addition, the number of recent publications on some representative thermoelectric materials is summarized, addressing the current research interests in this field. Thermoelectricity still need intensified scientific efforts to meet the practical demand. • Summarize most promising bulk thermoelectric materials. • Enumerate traditional thermoelectric materials and the corresponding performance enhancing strategies and developing status. • Some emerging and burgeoning materials with outstanding thermoelectric performance are reviewed. [ABSTRACT FROM AUTHOR]

p -type Na x Sn 1- x Se bulks were prepared by combining high pressure synthesis and spark plasma sintering. The final samples were characterized with XRD and SEM, and demonstrated strong structural anisotropy with the b-c planes in the grains preferentially orientated perpendicular to the SPS compressing direction. High pressure prompted Na doping process and increased the hole concentration up to 3.08 × 10 19 cm −3 in Na 0.02 Sn 0.98 Se, leading to significant increased electrical conductivity and power factor. Meanwhile, the thermal conductivity was substantially suppressed after Na doping. The highest ZT of 0.87 was achieved in the optimal Na 0.02 Sn 0.98 Se at 798 K measured along the direction perpendicular to the SPS compressing. [ABSTRACT FROM AUTHOR]