Effect of Eu2+ doping on structural, optical, magnetic and photovoltaic properties of ZnS quantum dots

ZnS and Eu2+: ZnS QDs with different doping concentrations were prepared by co-precipitation method at room temperature. It was observed that all samples form in cubic structure. The Eu2+ (0.1%): ZnS, Eu2+ (0.3%): ZnS and Eu2+ (0.5%): ZnS QDs display broad photoluminescence emission peaks at 513.5 nm, 511. 7 nm and 510.6 nm, respectively, are related to the Eu2+ intra-ion transition of 4f(6)d(1) - 4f(7). The M-H measurements indicated that unlike ZnS QDs, Eu2+: ZnS QDs with different doping concentrations indicates ferromagnetic behavior at room temperature. The incident photon to electron conversion efficiency (IPCE) is improved with the Eu2+ doping, which proposes the QD solar cell efficiency is able to be boosted by Eu2+ doping by reason of broadened absorption spectra. Accordingly, the data point out that Eu2+: ZnS QDs with different doping concentrations are able to be appropriate materials for photovoltaic and spintronic applications. (C) 2017 Elsevier Ltd. All rights reserved.