Xiaoyu Jia1,Joe Willis1,David Scanlon1,2
University College London1,University of Birmingham2
Xiaoyu Jia1,Joe Willis1,David Scanlon1,2
University College London1,University of Birmingham2
Transparent conducting oxides (TCOs) are a unique class of oxide materials that exhibit both transparency and electronic conductivity simultaneously. Thermoelectrics (TEs) are a class of materials that can directly convert heat and electricity mutually. Their Seebeck effect allow thermoelectric devices to recover waste heat and convert it into electrical power. The discovery of high performance transparent thermoelectric materials can potentially develop novel applications such as smart windows and screens with energy harvesting, cooling, and thermal sensing functionalities.<br/>In this project, NaGeSbO<sub>5</sub> was chosen due to its complex crystal structure, which typically leads to low lattice thermal conductivities. The (n-1)d<sup>10</sup>ns<sup>0</sup>sp<sup>0</sup> electronic configuration of Ge(IV) and Sb(V) is expected to yield a dispersive conduction band minimum, similar to the known TCOs.<br/>State-of-the-art ab initio calculations were performed using the VASP code to understand its thermoelectric capability. The initial steps involved evaluating the thermodynamic stability versus known compounds within Na-Ge-Sb-O phase space by CPLAP[1] and optimizing the geometry. Following this, we studied the band structure of NaGeSbO<sub>5</sub> and found its band gap is wide enough to ensure optical transparency. Subsequently, the band alignment was calculated using SURFAXE[2] to examine the doping preference. AMSET[3] code was then used to assess the charge transport properties, and an exploration of lattice dynamics was undertaken through the utilization of Phonopy[4] and hiPhive[5]. The stability at high temperature up to 1100 K has been experimentally confirmed.[6] The thermoelectric figure of merit (ZT) at this temperature was predicted to reach 1.09 at a specific carrier concentration, indicating the potential for setting a record in thermoelectric performance. In-depth defect engineering will be undertaken with the goal of attaining the optimal ZT.<br/>1. J. Buckeridge, D. O. Scanlon, A. Walsh, C. R. A. Catlow, <i>Computer Physics Communications</i>, 2014, <b>185</b>, 330.<br/>2. K. Brlec, D. Davies, D. O. Scanlon,<i> Journal of open source software</i>, 2021, <b>6</b>, 3171.<br/>3. A. M. Ganose, A. J. Jackson, D. O. Scanlon, <i>Nat. Commun.</i>, 2021, <b>12</b>, 2222.<br/>4. A. Togo, I. Tanaka, <i>Scripta materialia</i>, 2015,<b> 108</b>, 1359.<br/>5. F. Eriksson, E. Fransson, P. Erhart, <i>Adv. Theory Simul.</i>, 2019, <b>2</b>, 1800185.<br/>6. B. V. Mill, A. V. Butashin, S. Yu. Stefanovich, <i>Russian Journal of Inorganic Chemistry,</i> 1993, <b>38</b>, 947.