Enhancement of electroluminescence from TiO2/p+-Si heterostructure-based devices through engineering of oxygen vacancies in TiO2

Abstract

We report that electroluminescence (EL) from TiO2/p+-Si heterostructure-based devices can be significantly enhanced through a prior treatment of TiO2 films in argon (Ar) plasma. It is found that the Ar-plasma treatment introduces excess oxygen vacancies within a certain depth of TiO2 films. The increase in the concentration of oxygen vacancies leads to the enhancement of EL from TiO2/p+-Si heterostructure-based devices because oxygen vacancies are the light-emitting centers. This work demonstrates the use of defect engineering to improve the performance of oxide-based optoelectronic devices.