Regulation of Intrinsic Defects on the Electronic Structure and Optical Properties of Sn ₂ Nb ₂ O ₇

Transparent conductive oxides are essential in optoelectronics, but scarce high‐performance p‐type TCOs hinder all‐transparent device development. Sn ₂ Nb ₂ O ₇ , due to its hybridization characteristics of Sn‐5s and O‐2p orbitals at the valence band top, is highly compatible with the chemical modulation of valence band strategy, making it a promising candidate material for p‐type TCOs. In this study, first‐principles calculations were employed to systematically investigate the defect formation energy, electronic structure, and optical properties of eight intrinsic defects in Sn ₂ Nb ₂ O ₇ , aiming to explore its p‐type performance potential and optimize optoelectronic characteristics. The results show that under oxygen‐rich conditions, acceptor defects V _Sn , V _Nb , O _i , and Sn _Nb readily form spontaneously, whereas V _O , Sn _i , Nb _i , and Nb _Sn are significantly suppressed. Among these, V _Sn is a shallow acceptor defect that efficiently provides hole carriers, whereas V _Nb , although a strong acceptor, introduces deep energy levels leading to hole localization. Optical performance analysis demonstrates that the reflectivity and absorption coefficients of V _Sn and V _Nb defect systems exhibit excellent transparency in the visible light band without introducing additional light absorption, achieving synergistic optimization of p‐type conductivity and high visible light transparency. These findings provide critical theoretical support for the application of Sn ₂ Nb ₂ O ₇ in all‐transparent optoelectronic devices.