Spectroscopy of Topological Insulator Grid Nanostructures for Broadband Transparent Flexible Electrodes

In this work, we present 2D grids of topological insulator Bi₂Se₃ synthesized by a facile selective-area van der Waals epitaxy method for further enhancing the broadband transparency and reducing the material consumption. Large-area and high-quality Bi₂Se₃ grid nanostructures with controlled thickness and well-aligned positions are directly produced by a selective nucleation and epitaxy growth on prepatterned mica substrates. The robust surface states consisting of a single Dirac cone were observed in as-grown Bi₂Se₃ grid nanostructures by micro-spot angle-resolved photoemission spectroscopy (micro-ARPES). The 2D grid structures can significantly improve the visible transparency in comparison

 with continuous films, for the fact that the “holes” between grid lines is almost 100% transparent. The sheet resistance, on the other hand, can be compensated by using thicker grid strips. Therefore, optical transmittance and electrical conductance of the 2D topological gird can be tuned by changing its size and thickness.

Selective-Area Van der Waals Epitaxy of Topological Insulator Grid Nanostructures for Broadband Transparent Flexible Electrodes, by  Yunfan Guo et al, Adv. Mater. 25, 5959 (2013)