The thermal response of lead sensitized terbium emission in group II sulfide nanoparticles: importance of spatial proximity and band gap engineering

Abstract

Lead sensitized terbium emission in zinc sulfide nanoparticles is thermally irreversible, in which the spatial proximity of lead–terbium is important.

Doping-Guided Control of Lead-Sensitized Terbium Emission in Zinc Sulfide Nanoparticles: Implications for Lead Ion Sensing in Aqueous Media

“…The Tb−Pb spatial proximity and codopant electronic energy level alignments have been identified as important control parameters that guide the Tb 3+ emission brightening. 30 The results from the postsynthetically modified NPs suggest that synthetically codoped Zn(TbPb)S NPs should also exhibit this sensitization effect. A synthetic condition-dependent display of emission properties in doped semiconductor NPs finds notable literature precedence.…”

“…The broadening of the profile is a reflection of the smaller NP dimensionality (vide supra) and is consistent with our previous observations. 27,30 Formation of Zn(TbPb)S NPs with varying nominal amounts of Pb 2+ retains the characteristic bands of ZnS and does not have any dramatic effect to generate any additional phase that can be correlated to the formation of Pb-related phases. Thus, it can be unequivocally concluded that both Tb 3+ and Pb 2+ act as dopants in the ZnS matrix.…”

“…A Tb–Pb pair in Zn­(Tb)­S/Pb NPs presents such a scenario, where the postsynthetically added Pb 2+ to the Zn­(Tb)S NPs in the precation exchange reaction condition with [Zn­(Tb)­S]: [Pb 2+ ] = 1:10 –2 results in a five-fold enhancement of the Tb 3+ emission. − In these NPs, there are two sensitizers, namely, ZnS and Pb 2+ . The Tb–Pb spatial proximity and codopant electronic energy level alignments have been identified as important control parameters that guide the Tb 3+ emission brightening …”