Direct Synthesis of Hydrogen-Substituted Graphdiyne on Fluorine-Doped Tin Oxide Glass Substrates Using a Cu Sandwich Technique.

Hydrogen-substituted graphdiyne (HsGDY) is a two-dimensional material with an sp-sp carbon skeleton featuring a band gap and a porous structure that enhances ion diffusion. In previous reports, HsGDY growth was limited to metal substrates such as Cu, which then required transfer. Here, we developed a sandwich method that allows HsGDY to be grown directly on the target substrate. In this sandwich method, a Cu sheet is sandwiched between substrates. By optimizing the Cu sheet structure and growth time, we have succeeded in growing uniform, pinhole-free HsGDY films on FTO substrates. Raman peaks at 2217 cm (-C≡C-) and 883 cm (C-H bond) confirm the formation of HsGDY. Deconvoluted XPS spectra provide clear evidence of sp hybridization at 284.3 eV. Additionally, UV-visible spectra reveal that the band gap of HsGDY is 2.6 eV. This method is promising as an easy way to produce high-quality HsGDY films on arbitrary substrates. Preliminary tests demonstrated the potential application of HsGDY as a cathode material in dye-sensitized solar cells, achieving a maximum power conversion efficiency of 4.19%. These findings pave the way for the scalable, low-temperature synthesis of HsGDY films for advanced applications.