Degradation of Photoluminescence in CdTe Nanoparticles Due to Cl₂ Contamination

Abstract:

Nanostructured CdTe is proving a popular material for a variety of modern applications. Here, we report photoluminescent deterioration of CdTe due to Cl2 contamination. Cl2 gas was bubbled through a 2ml suspension of thioglycolic acid capped CdTe nanoparticles whilst photoluminescence was monitored. With the addition of only 0.02ml of Cl2 a loss of luminescence intensity was observed. Addition of 0.4ml of Cl2 resulted in a 70% loss of luminescence intensity, a 21nm shift in wavelength, and a large narrowing of the full-width-at-half-maximum. Cl2 attacks the Cd-S bond in the thiol capping layer of the nanoparticle, disrupting the passivation of the nanocrystal, and allowing the formation of non-radiative trap states. Smaller nanocrystals with a larger surface area to volume ratio are more heavily affected as is shown in the selective reduction of intensity from the smaller particles resulting in a narrower full-width-at-half-maximum and an apparent photoluminescence shift. A decrease in overall intensity is seen due to the lower number of emitting particles.

• Periodical: Advanced Materials Research (Volume 31)
• Pages: 150-152
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.31.150
• Online since: November 2007
• Authors: Hannah C. Gardner, Birju Patel, Cristina Bertoni, Diego E. Gallardo, Steve Dunn
• Keywords: CdTe, Chlorine, Nanoparticle, Photoluminescence (PL), Quantum Dot (QD)

References

[1] Y.G. Zheng, S.J. Gao and J.Y. Ying: Adv Mater. Vol 19, (2007) p.376.

[2] D.E. Gallardo, C. Bertoni, S. Dunn, N. Gaponik and A. Eychmüller: Adv Mater in press (2007).

[3] C. Bertoni, D.E. Gallardo, S. Dunn, N. Gaponik and A. Eychmüller: Appl Phys Lett Vol 90 (2007) 034107.

DOI: 10.1063/1.2433030

[4] J. Li, X. Hong, Y. Liu, D. Li, Y. Wang, J. Li, Y. Bai and T. Li: Adv Mater Vol 17 (2005) p.163.

[5] J. Britt and C. Ferekides: Appl Phys Lett Vol 62 (1993) p.2851.

[6] Z. Tang, N.A. Kotov and M. Giersig: Science Vol 297 (2002) p.237.

[7] M.A. Hernández-Fenollosa, D.P. Halliday, K. Durose, M.D. Campo and J. Beber: Thin Solid Films Vol 431-432 (2003) p.176.

DOI: 10.1016/s0040-6090(03)00238-4

[8] M.D.G. Potter, D.P. Halliday, M. Cousins and K. Durose: Thin Solid Films Vol 361-362 (2000) p.248.

DOI: 10.1016/s0040-6090(99)00782-8

[9] N. Gaponik, D.V. Talapin, A.L. Rogach, K. Hoppe, E.V. Shevchenko, A. Kornowski, A. Eychmüeller and H. Weller: J. Phys. Chem. B Vol 106 (2002) p.7177.

DOI: 10.1021/jp025541k

[10] J.E. Bowen Katari, V.L. Colvin and A.P. Alivisatos: J. Phys. Chem. Vol 98 (1994) p.4109.

[11] H. C. Gardner, D.E. Gallardo, S. Dunn, A. Eychmüller and N. Gaponik: J Nanosci. Nanotech. In press (2007).