Preparation and Photocurrent Generation of Silicon Nanosheets with Aromatic Substituents on the Surface

Soluble silicon nanosheets whose surfaces were modified with benzene-, naphthalene-, and carbazole-containing amino substituents (NS-Ph, NS-Np, and NS-Cz) were prepared by dehydrogenative coupling of layered polysilane Si 6 H 6 with the corresponding amines. X-ray diffraction (XRD) analysis of the dried samples revealed a clear diffraction peak at 13.2 Å for NS-Np, which was likely due to the stacked layers, whereas no clear signals were observed for NS-Ph and NS-Cz. The nanosheets produced UV–vis absorption and photoluminescence (PL) bands that were due to both the aromatic units and the silicon sheets consisting of two-dimensional silicon catenation. The strong tendency of NS-Np to form stacked layers was confirmed also from the PL spectrum that revealed a broad band likely ascribed to π-stacking. Photocurrent generation by use of the NS-Np and NS-Cz films was also investigated.