Acquisition of Optimum Co-sources of Sulfur MAA Capped-ZnS Quantum Dots Conditions for Photoluminescence Chlorine Sensor

ZnS quantum dots (QDs) has received a great attention due to its unique properties and wide applications. The objective of this work is to synthesize ZnS QDs by hydrothermal method and capped with mercaptoacetic acid (MAA) to be used as a chlorine sensor in the range from 1 to 35 mg/L. Optical, structural and morphological properties of MAA capped-ZnS QDs were investigated. MAA capped-ZnS QDs exhibited a cubic structure with an average diameter size of 8.8 nm. Photoluminescence (PL) spectra of the fabricated MAA capped-ZnS QDs revealed three basic emission peaks at 371, 423 and 486 nm due to level transitions involving of zinc vacancy, interstitial sulfur and zinc, respectively. The photostability of the MAA capped-ZnS QDs was examined after 14 months which retains 12% of the original PL intensity without any peak shift. The MAA capped-ZnS QDs PL intensity was changed linearly with the chlorine concentration in the range from 1 to 35 mg/L with correlation coefficient, sensitivity and limit of detection of 0.9782, 6.96×10-2 ppm-1 and 3.6 mg/L, respectively.

Reply to ‘Comment on “Zero-thermal-quenching and photoluminescence tuning with the assistance of carriers from defect cluster traps”’

In this response to the comments on our article, a series of Sr8Zn1−xSc(PO4)7:12%Tb3+ (SZ1−xSPO:12%Tb3+) phosphors were synthesized, and their photoluminescence behavior confirmed that zinc vacancy defects play a vital role in the SZ1−xSPO:12%Tb3+ phosphor.

Photoluminescence and point defect related emission of ZnO:Mn2+ micro/nanorod fabricated by co-precipitation method

Herein we study point defects and correlation to photoluminescence in ZnO nanorod. ZnO mirco/nanorod structure was successfully fabricated by co-precipitation method with highly homogeneous characteristics. When ion Mn+2 introduced into ZnO structure, the d-spacing distance of ZnO was increased from 0.248 nm to 0.295 nm due to the larger ionic radius of Mn2+ in comparison to Zn2+. The photoluminescence emission evolution of ZnO through doping and annealing processes hinted the relation of point defect transformations. We found that zinc interstitial, zinc vacancy and its related defects were responsible mainly for photoluminescence emission in annealing and/or Mn2+ doped samples.