Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 May 22;2(5):2231-2237.
doi: 10.1021/acsomega.7b00174. eCollection 2017 May 31.

Efficient Charge Extraction from CdSe/ZnSe Dots-on-Plates Nanoheterostructures

Sushma Yadav  1 , Buban Adhikary  1 , Puspanjali Tripathy  1 , Sameer Sapra  1
Affiliations

Efficient Charge Extraction from CdSe/ZnSe Dots-on-Plates Nanoheterostructures

Sushma Yadav et al. ACS Omega. .

Abstract

An efficient and a selective charge extraction from a new type of heterostructured material is demonstrated: the quasi-type-II structure formed upon deposition of ZnSe quantum dots on CdSe nanoplatelets, termed as CdSe/ZnSe dots-on-plates (DoPs) heterostructures. Insights into the charge extraction mechanism are gained from the present studies. Quenching experiments on nanoplatelets (NPLs) and DoPs using electron (benzoquinone) and hole (pyridine) quenchers show the possibility of electron extraction leaving behind the hole in the nanostructures. These outcomes indicate more labile electron extraction in comparison with the hole from these DoP structures vis-à-vis the plate only nanostructures, thereby enabling materials for devices requiring only one type of charges. In CdSe NPLs, the excitons are short-lived making them difficult for various applications involving charge separation. The CdSe/ZnSe DoPs could be alternate candidates for overcoming the difficulties involved with NPLs.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
(A) Conversion of CdSe NPL to CdSe/ZnSe DoP and (B) Quasi-type-II band alignment in the CdSe/ZnSe core/shell system.
Figure 2
Figure 2
Normalized absorption and PL spectra of (a) 4 ML CdSe NPLs, (b) 4 ML CdSe/ZnSe DoP, (d) 5 ML CdSe NPLs, and (e) 5 ML CdSe/ZnSe DoPs dissolved in hexane. Insets show that the NPLs exhibit green and red emission when illuminated with UV light. Time-resolved decay traces of (c) 4 ML and (f) 5 ML, NPLs and DoPs dissolved in hexane.
Figure 3
Figure 3
Left panel: 4 ML, right panel: 5 ML. (a, e) PXRD patterns of 4 and 5 ML thick CdSe/ZnSe, CdSe NPL, alongwith bulk CdSe WZ, CdSe ZB, and ZnSe ZB patterns. TEM images of (b, c) 4 ML and (f, g) 5 ML CdSe NPL and CdSe/ZnSe DoPs, respectively. HRTEM images of 4 ML CdSe/ZnSe DoPs can be seen in (d) and (h).
Figure 4
Figure 4
(a) Steady state and (b) time-resolved PL spectra of 4 ML CdSe NPLs without any quenchers, with BQ and Py. (c, d) Similar data for 4 ML CdSe/ZnSe DoP.
Figure 5
Figure 5
Schematic representation of the quenching experiment in CdSe NPL and CdSe/ZnSe DoP in the presence of a hole and electron quencher, using Py and BQ, respectively.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Talapin D. V.; Lee J. S.; Kovalenko M. V.; Shevchenko E. V. Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications. Chem. Rev. 2010, 110, 389–458. 10.1021/cr900137k. - DOI - PubMed
    1. Carey G. H.; Abdelhady A. L.; Ning Z.; Thon S. M.; Bakr O. M.; Sargent E. H. Colloidal Quantum Dot Solar Cells. Chem. Rev. 2015, 115, 12732–12763. 10.1021/acs.chemrev.5b00063. - DOI - PubMed
    1. Shirasaki Y.; Supran G. J.; Bawendi M. G.; Bulović V. Emergence of Colloidal Quantum-Dot Light-Emitting Technologies. Nat. Photonics 2013, 7, 13–23. 10.1038/nphoton.2012.328. - DOI
    1. Perfézou M.; Turner A.; Merkoçi A. Cancer Detection Using Nanoparticle-Based Sensors. Chem. Soc. Rev. 2012, 41, 2606–2622. 10.1039/C1CS15134G. - DOI - PubMed
    1. Medintz I. L.; Uyeda H. T.; Goldman E. R.; Mattoussi H. Quantum Dot Bioconjugates for Imaging, Labelling and Sensing. Nat. Mater. 2005, 4, 435–446. 10.1038/nmat1390. - DOI - PubMed