Abstract
In this study, the role of a zinc acetate precursor in improving the luminescence stability of purple-emitting CdS nanocrystals is investigated. The oleate-capped core of CdS nanocrystals exhibits intense photodarkening under prolonged UV excitation. From the results of photoluminescence experiments, we can observe that photobleaching is responsible for the degradation of temporal stability, i.e., decline in photoluminescence intensity. Herein, we demonstrate that by adding zinc acetate to the synthesis solution, one can enhance the photoluminescence stability by the complete suppression of the bleaching processes of nanocrystals. We can distinguish between the effects caused by zinc ions and those caused by acetate ligands. Acetate ligands improve the photoluminescence stability of the core of CdS nanocrystals. However, only when zinc acetate is used, the PL stability can be conserved at high excitation power. Simultaneously, we have studied the influence of zinc cations and acetate ligands on the kinetics of nanocrystal growth. The presented results underline the importance of short surface capping ligands and zinc cations in CdS nanocrystal synthesis. This study exhibits a new advantage of exploiting zinc acetate reagents in one-pot nanocrystal synthesis.
Highlights
Understanding the impact of synthesis precursors on the structural homogeneity/recurrence and optical properties of colloidal nanocrystals (NCs) is a key issue in the manufacturing of high quality and stable light emitters based on colloidal quantum dots.[1]
Luminophores despite a spectrally narrow emission and high photoluminescence quantum yield require temporal stability, especially at short wavelengths, for lightning applications;[2] this is hardly viable in case of bare NC cores, because small NC dimensions result in large amount of defect states at their surface
Zhang et al proposed a similar protocol for the synthesis, concluding a core/gradient alloy internal structure of the obtained CdS/ZnxCd1ÀxS NCs;[12] they started the reaction using CdO, OA, Zn(OAc)[2] and sulphur
Summary
Understanding the impact of synthesis precursors on the structural homogeneity/recurrence and optical properties of colloidal nanocrystals (NCs) is a key issue in the manufacturing of high quality and stable light emitters based on colloidal quantum dots.[1] Luminophores despite a spectrally narrow emission and high photoluminescence quantum yield require temporal stability, especially at short wavelengths (blue and purple), for lightning applications;[2] this is hardly viable in case of bare NC cores, because small NC dimensions result in large amount of defect states at their surface. Acetate-based precursors were shown to have strong impact on many optical and structural properties of nanostructures (nanobelts, nanorods and other structures).[7] Houtepan et al have reported the in uence of lead acetate on the dimensionality and shape of PbSe NCs.[8] Advanced structures such as CdSe platelets have been obtained using cadmium acetate.[9] Acetate reagents alter reaction kinetics, leading to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
