Yüksek Oranda Eş Parçacık Boyutlu CdSe Kuantum Noktaların Sentezi ve Optiksel Özelliklerinin Parçacık Boyutlarına Bağlılığı

Benzersiz elektriksel ve optik özelliklerinden dolayı yarıiletken kuantum noktalar birçok uygulama alanına sahiptirler. Son yıllarda CdSe kuantum noktalar en fazla tercih edilen nanomalzemelerin başında yer almaktadır. Sıcak enjeksiyon metodunu kullanarak yüksek oranda eş parçacık boyutuna sahip ve altıgen tip bir simetriye sahip çinko blend kristal tipinde CdSe kuantum noktalar sentezlendi. Elde edilen numunelerin yapıları ve özellikleri UV-Vis, fotolüminesans, XRD ve TEM karakterizasyon metotlarıyla aydınlatıldı. Sonuç olarak bakıldığında 2S ile 1P absorbsiyon geçişleri arasındaki farkın parçacık boyutu ile değişmediği fakat 1S ile 2S ve 1S ile 1P geçişleri arasındaki farkın parçacık büyüklüğü ile ters orantılı olduğu gözlemlendi. En küçük numunenin fotolüminesans spektrumunun FWHM değeri 25 nm’ye kadar düştüğü ve Stokes kayma miktarlarının 0.06 eV olduğu gözlemlendi.

Synthesis of Highly Monodisperse CdSe Quantum Dots and Size Dependency of Optical Properties

Semiconductor quantum dots have wide application areas as they have unique electrical and optical properties. In recent years, CdSe quantum dots are one of the most preferred nanomaterials. Highly monodisperse zinc blend CdSe quantum dots were synthesized using hot injection method. The structure and optical properties of the samples were determined by UV-Vis, photoluminescence, XRD and TEM methods. As a result, the difference between 2S-1P absorption transitions did not change with particle size. However, the difference between 1S-2S and 1S-1P transitions were found to be inversely proportional to particle size. The FWHM value of the photoluminescence spectrum of the smallest sample has decreased to 25 mm and Stokes shifts were observed to be 0.06 eV.

PDF

___

[1] Nozik A. J., Beard M. C., Luther J. M., Law M., Ellingson R. J., and Johnson J. C., ‘Semiconductor quantum dots and quantum dot arrays and applications of multiple exciton generation to third-generation photovoltaic solar cells’, Chemical Reviews, 110: 6873–6890, (2010).
[2] Elibol E., Elibol P. S., Cadırcı M., and Tutkun N., ‘Improving the performance of CdTe QDSSCs by chloride treatment and parameter optimization’, Materials Science in Semiconductor Processing, 96: 30– 40, (2019).
[3] McDonald S. A., Konstantatos G., Zhang S., Cyr P. W., Klem E. J. D., Levina L. and Sargent E. H., ‘Solutionprocessed PbS quantum dot infrared photodetectors and photovoltaics’, Nature Materials, 4: 138–142, (2005).
[4] Sukhovatkin V., Hinds S., Brzozowski L., and Sargent E. H., ‘Colloidal Quantum-Dot Photodetectors Exploiting Multiexciton Generation’, Science, 324: 1542–1544, (2009).
[5] Yang Y., Zheng Y., Cao W., Titov A., Hyvonen J., Manders J. R., Xue J., Holloway P. H. and Qian L., ‘Highefficiency light-emitting devices based on quantum dots with tailored nanostructures’, Nature Photonics, 9: 259– 265, (2015).
[6] Zhu S., Zhang J., Qiao C., Tang S., Li Y., Y. Wenjing, Li B., Tian L., Liu F., Hu R., Gao H., Wei H., Zhang H., Sunb H. and Yang B., ‘Strongly greenphotoluminescent graphene quantum dots for bioimaging applications’, Chemical Communications, 47: 6858– 6860, (2011).
[7] Shukla N. and Nigra M. M., ‘Synthesis of CdSe quantum dots with luminescence in the violet region of the solar spectrum’, Luminescence, 25:14–18, (2010). [8] Park J., Joo J., Soon G. K., Jang Y., and Hyeon T., ‘Synthesis of monodisperse spherical nanocrystals’, Angewandte Chemie - International Edition, 46: 4630– 4660, (2007).
[9] Yin Y. and Alivisatos A. P., ‘Colloidal nanocrystal synthesis and the organic-inorganic interface’, Nature, 437, : 664–670, (2005).
[10] M. Bawendi, ‘The Quantum Mechanics Of Larger Semiconductor Clusters, Annual Review of Physical Chemistry, 41 : 477–496, (1990).
[11] Mohamed M. B., Tonti D., Al-Salman A., Chemseddine A., and Chergui M., ‘Synthesis of high quality zinc blende CdSe nanocrystals’, The Journal of Physical Chemistry B, 109, :10533–7, (2005).
[12] Lee J., Sundar V. C., Heine J. R., Bawendi M. G., and Jensen K. F., ‘Full Color Emission from II-VI Semiconductor Quantum Dot-Polymer Composites’, Advanced Materials, 12, :1102–1105, (2000).
[13] Park J., Joo J., Soon G. K., Jang Y., and Hyeon T., ‘Synthesis of monodisperse spherical nanocrystals’, Angewandte Chemie - International Edition, 46: 4630– 4660, (2007).
[14] Klimov V. I., ‘Nanocrystal Quantum Dots’, in CRC Press Taylor & Francis Group, 2nd ed., Boca Raton London New York, 147–213, (2010)
[15] McElroy N., Page R.C., Espinbarro-Valazquez D., Lewis E., Haigh S., O'Brien P., Binks D.J.,‘Comparison of solar cells sensitised by CdTe/CdSe and CdSe/CdTe core/shell colloidal quantum dots with and without a CdS outer layer’, Thin Solid Films, 560: 65–70, (2014).
[16] Yu W. W., Qu L., Guo W., and Peng X., ‘Experimental Determination of the Extinction Coefficient of CdTe, CdSe, and CdS Nanocrystals’, Chemistry of Materials, 15(14): 2854–2860, ( 2003).
[17] Brus L., ‘Electronic wave functions in semiconductor clusters: Experiment and theory’, Journal of Physical Chemistry, 90(12): 2555–2560, (1986).
[18] Wakaoka T., Hirai K., Murayama K., Takano Y., Takagi H., Furukawa S. and Kitagawa S., ‘Confined synthesis of CdSe quantum dots in the pores of metalorganic frameworks’, Journal of Materials Chemistry C, 2(35): 7173–7175, (2014).
[19] Nightingale A. M. and Demello J. C., ‘Improving the ensemble optical properties of InP quantum dots by indium precursor modification’, Journal of Materials Chemistry C, 4(36): 8454–8458, (2016).
[20] Saha A., Chellappan K. V., Narayan K. S., Ghatak J., Datta R., and Viswanatha R., ‘Near-unity quantum yield in semiconducting nanostructures: Structural understanding leading to energy efficient applications’, The Journal of Physical Chemistry Letters., 4(20):3544– 3549, (2013).
[21] Norris D. and Bawendi M., ‘Measurement and assignment of the size-dependent optical spectrum in CdSe quantum dots’, Physical Review B: Condensed Matter and Materials Physics, 53(24):16338–16346, (1996).
[22] Murray C. B., Norris D. J., and Bawendi M. G., ‘Synthesis and Characterization of Nearly Monodisperse CdE (E = S, Se, Te) Semiconductor Nanocrystallites’, Journal of the American Chemical Society, 115(19): 8706–8715, (1993).
[23] Patterson A. L., ‘The scherrer formula for X-ray particle size determination’, Physical Review, 56(10): 978–982, (1939).