Recent advances of doping of SnO<SUB>2</SUB> nanocrystals for their potential applications

SnO<SUB>2</SUB> nanocrystal is a novel wide band gap n-type semiconductor which exhibits outstanding electrical, optical and electrochemical properties that can be exploited for solar cells, catalytic support materials, transparent electrodes and solid-state chemical sensors applications. The main focus of this article is to address the impacts of doping on the various properties of SnO<SUB>2</SUB> nanocrystals including optical, electrical, photocatalytic and gas sensing. Recently, emphasis is given on metal ion doped SnO<SUB>2</SUB> nanocrystals to enhance the electrical and optical properties. Metal ion doped SnO<SUB>2</SUB> nanocrystals are found to be potential candidates for gas-sensing devices. We will begin with the description of general synthetic methodologies for designing doped SnO<SUB>2</SUB> nanostructure materials. Interesting findings are that the application-based properties such as photocatalytic and gas sensing are increased manifold after doping of SnO<SUB>2</SUB> nanocrystals. Finally, a tentative outlook on future developments of this research field is given