Giant green emission enhancement of ZnO through desulfurization process
Résumé
The optical properties of ZnO has been widely investigated in detail. Typical photoluminescence (PL) of ZnO contains two parts of emission: near bandgap transition induced ultraviolet emission, and a relatively wide visible emission ranging from green to red, which is closely related to concentration of the structural defects. While the green luminescent has been reported to be associated with oxygen vacancies Vo. In this work, we report on an efficient technique namely desulfurization to increase the amount of oxygen vacancy in a ZnO nanowires array. In the case of the desulfurized sample the PL is increased by more than 1 order of magnitude as to compare with the sulfurized one and more than 2 orders of magnitude as to compare with the as grown sample. Structural analysis as well as morphological analysis confirm the origin of the green band emission enhancement in PL emission. Samples preparation as well an in-depth analysis including quantum efficiency will be presented and discussed within the frame of new rare-earth free phosphor material.