CdSeS/ZnS Kuantum Nokta Katkılı 5CB Nematik Sıvı Kristalinde Optik Bant Aralıklarının İncelenmesi

Yıl 2018, , 123 - 130, 31.01.2018

Gülsüm Kocakülah , Kadir Gökşen , Oğuz Köysal

https://doi.org/10.29130/dubited.362037

Öz

Bu çalışmada, CdSeS/ZnS alaşım
kuantum nokta katkılı 5CB (4-pentyl-4′-cyanobiphenyl) nematik sıvı kristal
yapının optik bant aralığı değerleri incelenmiştir. CdSeS/ZnS alaşım kuantum
nokta, 5CB nematik sıvı kristal yapı içerisine ağırlıkça % 0,05, % 0,1 ve % 0,15
oranlarında katkılanarak optik bant aralığı değerleri elde edilmiştir. Deneysel
sonuçlara göre kuantum nokta katkılanmasıyla optik bant aralığı değerlerinin
azaldığı gözlemlenmiştir. Elde edilen sonuçlar, CdSeS/ZnS alaşım kuantum nokta
yapının sıvı kristal tabanlı cihaz uygulamalarında elektro-optik özellikleri
değiştirebilen alternatif bir malzeme olarak kullanılabileceğini
göstermektedir.

Anahtar Kelimeler

Nematik sıvı kristal, Kuantum nokta, Optik bant aralığı

Investigation of Optical Band Gap of CdSeS/ZnS Quantum Dot Doped 5CB Nematic Liquid Crystals

Öz

In this study, optical band gap values of 5CB (4-pentyl-4 'cyanobiphenyl) nematic liquid crystal structure doped with CdSeS/ZnS alloyed quantum dots are investigated. The CdSeS/ZnS alloyed quantum dot was doped into the 5CB nematic liquid crystal structure at 0.05, 0.1 and 0.15 % wt/wt and optical band gap values were obtained. According to experimental results, optical band gap values decrease with quantum dot doping. The results show that the CdSeS/ZnS alloyed quantum dots can be alternative materials used in liquid crystal based device applications whose electro-optical properties are able to be easily modified.

Anahtar Kelimeler

Nematic liquid crystal, Quantum dot, Optical band gap

Kaynakça

• [1] J. Mirzaei, M. Reznikov, T. Hegmann “Quantum Dots As Liquid Crystal Dopants,” Journal of Materials Chemistry, vol. 22, no. 42, pp. 22350-22365, 2012.
• [2] A. Kumar, A. M. Biradar, “Effect of Cadmium Telluride Quantum Dots on The Dielectric And Electro-Optical Properties Of Ferroelectric Liquid Crystals,” Physical Review E, vol. 83, no. 4, pp. 041708, 2011.
• [3] P. K. Tripathi, A. Misra, K. Pandey and R. Manohar, “Study on dielectric and optical properties of ZnO doped nematic liquid crystal in low frequency region,” Chem. Commun, vol. 1, pp. 20-26, 2013.
• [4] E. A. Konshina, I. F. Galin and E. O. Gavrish, “Reversible capacitance change of nematic liquid crystal cell doped with semiconductor CdSe/ZnS quantum dots,” Universal Journal of Materials Science, vol. 2, no. 1, pp. 1-4, 2014.
• [5] P. Reiss, M. Protiere and L. Li, “Core/shell semiconductor nanocrystals,” small, vol. 5, no. 2, pp. 154-168, 2009.
• [6] I. Mora-Sero, S. Giménez, F. Fabregat-Santiago, R. Gómez, Q. Shen, T. Toyoda and J. Bisquert, “Recombination in quantum dot sensitized solar cells,” Accounts of chemical research, vol. 42, no. 11, pp. 1848-1857, 2009.
• [7] A. J. Nozik, M. C. Beard, J. M. Luther, M. Law, R. J. Ellingson, J. C. Johnson, “Semiconductor quantum dots and quantum dot arrays and applications of multiple exciton generation to third-generation photovoltaic solar cells, “Chemical reviews, vol. 110, no. 11, pp. 6873-6890, 2010.
• [8] B. A. Kairdolf, A. M. Smith, T. H. Stokes, M. D. Wang, A. N. Young and S. Nie, “Semiconductor quantum dots for bioimaging and biodiagnostic applications,” Annual Review of Analytical Chemistry, vol. 6, pp. 143-162, 2013.
• [9] O. Köysal, “Azo boya ve fulleren (C60) katkılı nematik sıvı kristallerin elektro-optik özelliklerinin incelenmesi,” Doktora tezi, Fizik Bölümü, Gebze Yüksek Teknoloji Enstitüsü, Kocaeli, Türkiye, 2007.
• [10] G. Pathak, S. Pandey, R. Katiyar, A. Srivastava, R. Dabrowski, K. Garbat, R. Manohar “Analysis of photoluminescence, UV absorbance, optical band gap and threshold voltage of TiO 2 nanoparticles dispersed in high birefringence nematic liquid crystal towards its application in display and photovoltaic devices,” Journal of Luminescence.
• [11] M. Mishra, R. S. Dabrowski, R. Dhar, “Thermodynamical, optical, electrical and electro-optical studies of a room temperature nematic liquid crystal 4-pentyl-4′-cyanobiphenyl dispersed with barium titanate nanoparticles” Journal of Molecular Liquids, vol. 213, pp. 247-254, 2016.
• [12] P. R. Supreet, S. Kumar, K. K. Raina, “Effect of dispersion of gold nanoparticles on the optical and electrical properties of discotic liquid crystal,” Liquid Crystals, vol. 41, no. 7, pp. 933-939, 2014.
• [13] E. B. Barmatov, D. A. Pebalk, M. V. Barmatova, “Influence of silver nanoparticles on the order parameter of liquid crystalline polymers. Liquid crystals,” vol. 33, no. 9, pp.059-1063, 2006.
• [14] U. B. Singh, M. B. Pandey, R. Dhar, R. Verma, S. Kumar, “Effect of dispersion of CdSe quantum dots on phase transition, electrical and electro-optical properties of 4PP4OB,” Liquid Crystals, vol. 43, no. 8, pp. 1075-1082, 2016.
• [15] R. Manohar, S. Manohar, V. S. Chandel, “Dielectric behaviour of pure and dye doped nematic liquid crystal BKS/B07,” Materials Sciences and Applications, vol. 2, no. 7, pp. 838, 2011.
• [16] S. E. Hicks, S. P. Hurley, Y. C. Yang, D. K. Yang, “Electric Polarization Frozen By A Polymer Network İn Nematic Liquid Crystals Soft Matter,” vol. 9, no. 14, pp. 3834-3839, 2013.
• [17] S. Ilıcan, Y. Çağlar, M. Çağlar, “CdZnS ve ZnO Yarı iletken Filmlerinin Yasak Enerji Aralıkları. Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi,” c. 9, s. 1, ss. 48-54,2005.
• [18] H. Kızılçaoğlu, K. Gökşen, Y. Köysal, “Amorf Hidrojenlenmiş Karbon İnce Filmlerin Yasak Enerji Bant Aralıklarının Optiksel İncelenmesi,” Düzce Üniversitesi Bilim ve Teknoloji Dergisi, c. 4, s. 1, 2016.
• [19] T. Şimşek, K. Gökşen, “Çeşitli Gaz Akış Hızı Koşullarında Üretilen Hidrojenlenmiş Amorf Karbon İnce Filmlerin Optik Bant Aralıklarının İncelenmesi,” Düzce Üniversitesi Bilim ve Teknoloji Dergisi (Dübited), c. 5, s. 1. 2017.
• [20] U. B. Singh, D. Singh, S. Kumar, R. Dhar, M. B. “Pandey The optical properties of quantum dots in anisotropic media. Journal of Molecular Liquids,” vol. 241, pp.1009-1012, 2017.