First-principles study of strain effect on the thermoelectric properties of LaP and LaAs. Issue 33 (16th August 2021)

• Record Type: Journal Article
• Authors: Lin, Chia-Min; Chen, Wei-Chih; Chen, Cheng-Chien
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 33(2021)
• Page Start: 18189
• Page End: 18196
• Publication Date: 2021-08-16
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp02871e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The thermoelectric figure of merit ZT value of quantum materials lanthanum monopnictides can be boosted to ZT > 2 by isotropic strain at high temperature. Abstract : Rare-earth monopnictides have attracted much attention due to their unusual electronic and topological properties for potential device applications. Here, we study rock-salt structured lanthanum monopnictides LaX (X = P, As) by density functional theory (DFT) simulations. We show systematically that a meta-GGA functional combined with scissor correction can efficiently and accurately compute the electronic structures on a fine DFT k -grid, which is necessary for converging thermoelectric calculations. We also show that strain engineering can effectively improve the thermoelectric performance. Under the optimal conditions of 2% isotropic tensile strain and carrier concentration n = 3 × 10 20 cm −3, LaP at a temperature of 1200 K can achieve a figure of merit ZT value >2, which is enhanced by 90% compared to the unstrained value. With carrier doping and strain engineering, lanthanum monopnictides thereby could be promising high-temperature thermoelectric materials.