Synthesis and Photoluminescence Characterization of 3-MPA Capped CdZnTe Quantum Dots

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Published Sep 11, 2021
Kiran John U. Dr. Siby Mathew

Abstract

Abstract

Semiconductor quantum dots have attracted the scientific community due to their size depended physiochemical properties. The II-VI semiconductors like CdTe, CdSe, CdS, ZnTe, ZnSe, etc., have been potential candidates for applications like bio labelling, solar cells, lasers, light-emitting diodes, and optoelectronic devices. These quantum dots been explored by many research communities [1-2]. The cadmium-based quantum dots quite appreciable among these due to the high stability, photoluminescence and quantum yield but the limiting factor for this is the toxicity of the cadmium. So, in order to overcome this difficulty efforts have been made to prepare cadmium-free semiconductor quantum dots but the photostability and quantum yield for these quantum dots were less. Ternary II-VI alloy semiconductors quantum dots were proposed as the solution to these difficulties. The alloy semiconductor quantum dots have the advantage of size and composition tuneable optical, photoluminescence and electronic properties. Among the ternary II-VI quantum dots, ZnCdSe, CdZnS, ZnCdS, ZnSTe and CdZnTe alloyed quantum dots have been subject of keen investigations because of their wider adjustable band gap and high quantum yield compared with binary quantum dots. The traditional synthesis part of alloy quantum dots follows long reaction time and requires sophisticated inert atmosphere. The challenge is still open to simplify the complexity of the synthesis part without compromising the photoluminescent properties [3-4].

Ternary CdZnTe alloy quantum dots are an excellent candidate for photoluminescence applications due to the higher quantum yield, narrow emission spectrum and wide range of emission spectrum range. The composition tailored band gap and emission spectrum provides an additional advantage compared to the binary CdTe quantum dots. The alloying effect reduces the toxicity which makes CdZnTe quantum dots quite favourable for biolabeling and cell imaging applications [5]. Here the CdZnTe quantum dots were synthesized using 3-MPA as the capping agent. The conventional method uses NaHTe or H2Te for the tellurium sources, which are unstable in air and the latter is highly inflammable. Due to these difficulties the inert gas atmosphere become necessary using these sources [6]. The synthesis procedure performed using Na2TeO3 as the source of tellurium have the advantages of air stability and the synthesis can proceed without providing inert gas atmosphere [5-6]. The experimental procedure for the water soluble CdZnTe quantum dots is illustrated in fig. 1. A. The quantum dot capping by MPA confirmed in FTIR spectrum. The optical absorption spectrum gives an excitonic peak at 527 nm. The photoluminescence spectrum gives a high intense emission peak at 567 nm at an excitation wavelength of 380 nm which is given in fig. 1. B. The optical and PL parameters are tabulated in table 1. The bandgap of the quantum dot estimated using Tauc relation. The photoluminescence emission corresponds to yellow fluorescence. High photoluminescence emission intensity was observed when the prepared CdZnTe quantum dots diluted to 0.66 v/v%. The high intense yellow fluorescent CdZnTe quantum can be placed as potential candidates for fluorescent probes, biolabeling and cell imaging applications.

Fig.1. A. experimental setup B. Photoluminescence emission spectrum.

Fig.1. A. experimental setup B. Photoluminescence emission spectrum.

Table 1. Optical and PL parameters of CdZnTe quantum dots

Sample

Absorption coefficient α (cm-1)

 Exciton peak (nm)

Emission peak (nm)

CdZnTe       quantum dots

2.06

527

567

 

References

[1] Lu, Xiaoting, et al. Analytica chimica acta 1047,163-171 (2019).

https://doi.org/10.1016/j.aca.2018.10.002

[2] Al-Rasheedi, Asmaa, et al. Journal of Materials Science: Materials in Electronics 28.12, 9114-9125. (2017).

https://doi.org/10.1007/s10854-017-6645-8

[3] Jose, A. R., A. E. Vikraman, and K. Girish Kumar, New Journal of Chemistry 41.19, 10828-10834 (2017).

https://doi.org/10.1039/C7NJ00795G

[4] Cheng, Jingwei, et al. Journal of alloys and compounds 589, 539-544. (2014).

https://doi.org/10.1016/j.jallcom.2013.11.207

[5] Balakrishnan, Janani, et al. Journal of Physics D: Applied Physics 54.14, 145103 (2021).

https://doi.org/10.1088/1361-6463/abd6d3

[6] Tripathi, S. K., Ramneek Kaur, and Mamta Sharma. Applied Physics A 118.4, 1287-1295 (2015).

https://doi.org/10.1007/s00339-014-8833-1

How to Cite

John U., K., & Mathew, S. (2021). Synthesis and Photoluminescence Characterization of 3-MPA Capped CdZnTe Quantum Dots . SPAST Abstracts, 1(01). Retrieved from https://spast.org/techrep/article/view/264
Abstract 9 |

Article Details

Keywords

CdZnTe quantum dots, Photoluminescence, Tauc plot, Biolabeling, fluorescent probes

References
[1] Lu, Xiaoting, et al. Analytica chimica acta 1047,163-171 (2019).
https://doi.org/10.1016/j.aca.2018.10.002
[2] Al-Rasheedi, Asmaa, et al. Journal of Materials Science: Materials in Electronics 28.12, 9114-9125. (2017).
https://doi.org/10.1007/s10854-017-6645-8
[3] Jose, A. R., A. E. Vikraman, and K. Girish Kumar, New Journal of Chemistry 41.19, 10828-10834 (2017).
https://doi.org/10.1039/C7NJ00795G
[4] Cheng, Jingwei, et al. Journal of alloys and compounds 589, 539-544. (2014).
https://doi.org/10.1016/j.jallcom.2013.11.207
[5] Balakrishnan, Janani, et al. Journal of Physics D: Applied Physics 54.14, 145103 (2021).
https://doi.org/10.1088/1361-6463/abd6d3
[6] Tripathi, S. K., Ramneek Kaur, and Mamta Sharma. Applied Physics A 118.4, 1287-1295 (2015).
https://doi.org/10.1007/s00339-014-8833-1
Section
GM2- Microsystems & Nanotechnology