Well Dispersed SnO $_\textbf{2}$ Nanoclusters Preparation and Modulation of Metal-Insulator Transition Induced by Ionic Liquid

Tin dioxide (SnO $_2$ ) has attracted broad interest due to its particular gas-sensor property. Nano- or atom-scale SnO $_2$ material has always been the aim in order to ultimately improve the sensitivity. However, until now, it remains difficult to synthesize SnO $_2$ nanoclusters by using traditional methods. In the present work, we have achieved the preparation of SnO $_2$ nanoclusters by using the cluster beam deposition technique. The obtained nanoclusters were well characterized by high resolution transmission electron microscope HR-TEM. Results indicated the formation of the well-dispersed SnO $_2$ nanoclusters with uniform size distribution (5 $-$ 7 nm). Furthermore, an obvious metal insulator transition was observed by gating with ionic liquid. Combined with theory calculation, the corresponding mechanism was systematically analyzed from oxygen vacancy induced electron doping.