Lattice Plainification Leads to High Thermoelectric Performance of P-type PbSe Crystals.

Thermoelectrics has application in power generation and refrigeration. Sine the only commercial Bi2Te3 has low abundance Te, PbSe gets attention. This work enhanced the near room temperature performance of p-type PbSe through enhancing carrier mobility via lattice plainification. Composition controlled and Cu doped P-type PbSe crystals were grown through physical vapor deposition. Results exhibited an enhanced carrier mobility ∼2578 cm2 V-1 s-1 for Pb0.996Cu0.0004Se. Microstructure characterization and density functional theory calculations verified the introduced Cu atoms filled Pb vacancies, realizing lattice plainification and enhancing the carrier mobility. The Pb0.996Cu0.0004Se sample achieved a power factor ∼ 42 μW cm -1 K-2 and a ZT ∼ 0.7 at 300 K. The average ZT of it reached ∼0.9 (300-573 K), resulting in a single-leg power generation efficiency of 7.1% at temperature difference of 270 K, comparable to that of p-type commercial Bi2Te3. A 7-pairs device paired the p-type Pb0.996Cu0.0004Se with the n-type commercial Bi2Te3 showed a maximum cooling temperature difference ∼42 K with hot side at 300 K, about 65% of that of the commercial Bi2Te3 device. This work highlights potential of p-type PbSe for power generation and refrigeration near room temperature and hope to inspire researches on replacing commercial Bi2Te3. This article is protected by copyright. All rights reserved.