Charge transfer and field emission characteristics of TiO₂@CNTs nanocomposite: Effect of TiO₂ crystallinity

In this work, the correlation between field emission characteristics of TiO₂@CNTs nanocomposite and TiO₂ crystallinity was investigated via charge transfer mechanism. It was discovered that CNTs covered with amorphous TiO₂ showed the lowest turn-on voltage and highest enhancement factor followed by CNTs combined with crystalline TiO₂ and then pristine CNTs, consequently. The increased performance was attributed to the existence of oxygen vacancies in amorphous TiO₂ which due to their donor-like nature resulted in more efficient charge transfer between TiO₂ and CNTs. Thus, the surface of nanocomposite became occupied by a higher number of electrons which influenced positively on the application as field emission cathode.