Computational Prediction of an n-type Transparent Conducting Oxide F-doped Sb₂O₅

Transparent conducting oxides possess a unique combination of optical transparency and electrical conductivity, making them indispensable in optoelectronic applications. ¹ However, the heavy dependence on a small number of established transparent conducting oxides (In₂O₃, SnO₂, ZnO and Ga₂O₃) places limitations on the number and types of devices they can support. Additionally, the high cost due to the scarcity of rare elements raises concerns about their long-term sustainability and large-scale production. ² Discovering more wide band gap oxides that can be doped to display metallic-like conductivity is therefore necessary.<br/><br/>In this work, we use the PBE0 hybrid functional to investigate the defect chemistry of the binary Sb(V) system, Sb₂O₅. ³ We observe a large optical band gap over 3.6 eV, enabling transparency. The calculated Sb₂O₅ electronic structure shows a dispersive conduction band minimum with low electron effective masses, revealing its n-type properties. Our defect analysis reveals that Sb₂O₅does not display metallic-like conductivity when nominally undoped, however, F-doped Sb₂O₅ displays degenerate n-type transparent conducting behaviour. Our band alignment calculations demonstrate that Sb₂O₅ has a larger electron affinity than the established transparent conductors, which can facilitate electron extraction for organic solar cells applications. The findings of this under-explored Sb(V) binary system prove the feasibility and potential for Sb(V)-based materials to be promising transparent conducting oxides.<br/><br/><br/>(1) Jackson, A. J.; Parrett, B.; <i>et al. </i><i>ACS Energy Lett.</i> <b>2022</b>, 3807–3816.<br/>(2) Mineral Commodity Summaries 2023. <b>2023</b>.<br/>(3) Adamo, C.; Barone, V. <i>The Journal of Chemical Physics</i> <b>1999</b>, <i>110</i> (13), 6158–6170.