Silicene Quantum Dots Confined in Few-Layer Siloxene Nanosheets for Blue-Light-Emitting Diodes

Two-dimensional silicon-based materials have unique physical and chemical properties due to high surface area and quantum confinement effects. Herein, a topochemical reaction method is used for preparing silicene quantum dots confined in few layer siloxene nanosheets with FeCl3·6H2O as oxidant, which shows a thickness less than 2 nm. The experimentally prepared siloxene nanosheets are dispersible, with silicene quantum dots having an average diameter less than 5 nm. The silicene quantum dots are self-organized through the oxidation of FeCl3, showing unique optical properties of blue emission. The UV–visible absorption and PL emission spectra indicate the quasi-direct band gap transition to the emission. Besides, the few-layer siloxene nanosheets with silicene quantum dots have a radiative lifetime of 1.098 ns at an emission wavelength of 435 nm, which derives from the quasi-direct band transition of silicene quantum dots. Such two-dimensional nanosheets of silicon possess potential applications for the emitting layer materials of blue light-emitting diodes (LED).