Chemical Intercalation of Topological Insulator Grid Nanostructures for High-Performance Transparent Electrodes.

2D layered nanomaterials with strong covalent bonding within layers and weak van der Waals' interactions between layers have attracted tremendous interest in recent years. Layered Bi2 Se3 is a representative topological insulator material in this family, which holds promise for exploration of the fundamental physics and practical applications such as transparent electrode. Here, a simultaneous enhancement of optical transmittancy and electrical conductivity in Bi2 Se3 grid electrodes by copper-atom intercalation is presented. These Cu-intercalated 2D Bi2 Se3 electrodes exhibit high uniformity over large area and excellent stabilities to environmental perturbations, such as UV light, thermal fluctuation, and mechanical distortion. Remarkably, by intercalating a high density of copper atoms, the electrical and optical performance of Bi2 Se3 grid electrodes is greatly improved from 900 Ω sq-1 , 68% to 300 Ω sq-1 , 82% in the visible range; with better performance of 300 Ω sq-1 , 91% achieved in the near-infrared region. These unique properties of Cu-intercalated topological insulator grid nanostructures may boost their potential applications in high-performance optoelectronics, especially for infrared optoelectronic devices.