Nanocomposites and nanomaterials

Properties of CdTe nanocrystals doped with manganese
Dremliuzhenko K.S. , Kapush O.A.
V.E. Lashkaryov Institute of Semiconductor Physics NAS of Ukraine Prospect Nauki, 41, Kyiv-03039, Ukraine. 
E-mail: xeniyadr93@gmail.com

Semiconductor nanomaterials are of great interest to researchers because of their unique optical and electrical properties, photosensitivity resistance, wide absorption band and narrow spectra of emission. CdTe nanocrystals (NCs) are characterized by the ability to regulate the radiation band from 400 to 700 nm by changing the size due to quantum containment, and are extensively studied due to the possibilities of their application in industry and biomedicine, in particular for light-emitting devices (LEDs) [1 ], photonic crystals [2], nonlinear optical devices [3] and biological labels [4] creation. However, this study of semiconductor nanocrystals does not stop. Already investigated substances can be modified, which results in the significant properties change. For example, the injection a dopant to a NC semiconductor is one way of controlling the formation of a radiation spectrum in the desired spectral range.
In this paper, CdTe NCs were prepared by the standard method of colloidal synthesis [5] at room temperature. CdI2 was used as a source of Cd2 + ions and H2Te gas was a source of Te2 ions, electrochemically obtained in a galvanostatic cell. To stabilize the surface of the nanocrystals used thioglycolic acid. As a dopant in the synthesis, paramagnetic elements (Mn2 +) were used. CdTe NС doped with such elements have magnetic resonance properties, which makes them a promising material for detecting objects in magnetic fields. At the same time, atoms of manganese have the strongest magnetic properties, in comparison with other paramagnetic elements, which are connected with electrons and atomic nucleus influence, which leads to  extremely complexity of NС quantum systems doped with manganese.
This research revealed how the manganese impurities injection affects the properties of the CdTe NC. In particular, the influence of the dopant concentration and pH of the medium has been investigated.
The influence of heating the CdTe samples, doped with manganese, has been studied independently. Dependence of radiation intensity on heating time was investigated.
It was discovered that heating of received doped samples increases the luminescence ability of nanoparticles.

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