10.1186/2228-5326-3-31

Defect-related blue emission from ultra-fine Zn1−xCdxS quantum dots synthesized by simple beaker chemistry

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  • Jeotikanta Mohapatra*1,
  1. Centre for Research in Nanotechnology and Science (CRNTS), Indian Institute of Technology Bombay, Powai, Mumbai, 40076, IN
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Published in Issue 2013-05-08

How to Cite

Mohapatra, J. (2013). Defect-related blue emission from ultra-fine Zn1−xCdxS quantum dots synthesized by simple beaker chemistry. International Nano Letters, 3(1 (December 2013). https://doi.org/10.1186/2228-5326-3-31
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Abstract

Abstract It has been possible to incorporate cadmium ions in ZnS quantum dots (QDs). It is studied how the substitution of Cd 2+ ions by zinc ions affects the structural, morphological, and optical properties of ZnS QDs. Zn 1− x Cd x S QDs are prepared by a simple beaker chemistry approach and characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy, and UV-visible and photoluminescence (PL) spectroscopies. XRD studies confirmed that all the prepared samples are in zinc-blende phase. With the increase of cadmium content, the diffraction peaks shifted towards lower diffraction angles and the lattice constant increased linearly. Optical studies revealed that the strong absorption edge also shifted towards the higher wavelength region with the increase of Cd content. Hence, the optical bandgap of the QDs decreases with the increase of Cd content. Due to the quantum confinement of the carriers in the QDs, the bandgap energy is higher than that of the corresponding bulk material. The PL spectrum of the undoped ZnS QDs contains five peaks (centered at 365, 400, 420, 450, and 470 nm) which are attributed to the recombination of the defect states of ZnS.

Keywords

  • Quantum dots,
  • Beaker chemistry,
  • Optical properties
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