Journal of Applied Science and Engineering

Published by Tamkang University Press

1.30

Impact Factor

1.60

CiteScore

Che-Hung Hsu1 and Shu-Chun Yang This email address is being protected from spambots. You need JavaScript enabled to view it.1

1Department of Physics, Tamkang University, Tamsui, Taiwan 251, R.O.C.


 

Received: March 20, 2015
Accepted: June 2, 2015
Publication Date: June 3, 2015

Download Citation: ||https://doi.org/10.6180/jase.2015.18.2.07  


ABSTRACT


Raman scattering spectra of blue light-emitted organic conjugated polymer, ladder-type poly para-phenylene with a phenyl ring in the side chain (Ph-LPPP), in the form of powder with trace-concentrations of metallic impurities under various pressures are measured. We find that Raman spectra shift to higher frequency with the increase of pressure, indicating a strong electron-phonon interaction. We also find that the shift rates of Raman peaks from the backbone of Ph-LPPP are different comparing to our early observations of Raman spectra of methyl substituted ladder-type poly (Me-LPPP). Planarization under pressure, therefore, electronic delocalization is observed, which is also discovered from the optical properties of Ph-LPPP.


Keywords: Raman Scattering Spectrum, Hydrostatic Pressure, Conjugated Polymer, Electron-phonon Interaction


REFERENCES


  1. [1] So, F. and Kondakov, D., “Degradation Mechanisms in Small-molecule and Polymer Organic Light-emitting Diodes,” Advanced Materials, Vol. 22, No. 34, pp. 37623777 (2010). doi: 10.1002/adma.201090111
  2. [2] Tasch, S., Niko, A., Leising, G. and Scherf, U., “Highly Efficient Electroluminescence of New Wide Band Gap Ladder-type Poly(Para-phenylenes),” Applied Physics Letters, Vol. 68, No. 8, p. 1090 (1996). doi: 10.1063/ 1.115722
  3. [3] Bernius, M. T., Inbasekaran, M., O’Brien, J. and Wu, W., “Progress with Light-emitting Polymers,” Advanced Materials, Vol. 12, No. 23, pp. 7371750 (2000). doi: 10.1002/1521-4095(200012)12:233.0.CO;2-N
  4. [4] Chen, L.-M., Hong, Z., Li, G. and Yang, Y., “Recent Progress in Polymer Solar Cells: Manipulation of Polymer: Fullerene Morphology and the Formation of Efficient Inverted Polymer Solar Cells,” Advanced Materials, Vol. 21, No. 1415, pp. 14341449 (2009). doi: 10.1002/adma.200802854
  5. [5] Grem, G., Leditzky, G., Ullrich, B. and Leising, G., “Realization of a Blue-light-emitting Device Using Poly(p-phenylene),” Advanced Materials, Vol. 4, No. 1, pp. 3637 (1992). doi: 10.1002/adma.19920040 107 [6] Satish, P., “Ladder Polymers for Photonic Application,” PhD. Dissertation, Bergischen Universitat (2004).
  6. [7] Leising, G., Tasch, S., Graupner, W., ed. by Skotheim, T. A., Elsenbaumer, R. L. and Reynolds, J. R., Handbook of Conducting Polymers, 2nd ed., Marcel Dekker, New York, pp. 847880 (1998).
  7. [8] Paudel, K., Knoll, H., Chandrasekhar, M. and Guha, S., “Tuning Intermolecular Interactions in Dioctyl-substituted Polyfluorene Via Hydrostatic Pressure,” The Journal of Physcal Chemistry A, Vol. 114, No. 13, pp. 46804688 (2010). doi: 10.1021/jp911778r
  8. [9] Guha, S., Graupner, W., Yang, S., Chandrasekhar, M., Chandrasekhar, H. R. and Leising, G., “Optical Properties of Poly(Para-phenylenes) Under High Pressure,” Physica Status Solidi (b), Vol. 211, No. 1, pp. 177188 (1999). doi: 10.1002/(SICI)1521-3951(199901)211:1 3.0.CO;2-K
  9. [10] Cuff, L., Kertesz, M., Scherf, U. and Müllen, K., “Interpretation of the Vibrational Spectra of Planarized Poly-p-phenylene,” Synthetic Metals, Vol. 69, No. 1 3, pp. 683684 (1995). doi: 10.1016/0379-6779(94) 02613-4
  10. [11] Cuff, L. and Kertesz, M., “Theoretical Prediction of the Vibrational Spectrum of Fluorene and Planarized Poly(p-phenylene),” The Journal of Physical Chemistry, Vol. 98, No. 47, pp. 1222312231 (1994). doi: 10.1021/j100098a017
  11. [12] Godon, C., Buisson, J. P., Lefrant, S., Sturm, J., Klemenc, M., Graupner, W., Leising, G., Mayer, M., Schlüter, A. D. and Scherf, U., “Vibrational Analysis of Derivatives of Polyparaphenylene,” Synthetic Metals, Vol. 84, No. 13, pp. 673674 (1997). doi: 10.1016/S0379- 6779(96)04103-3
  12. [13] Somitsch, D., Wenzl, F. P., List, E. J. W., Wilhelm, P., Scherf, U., Leising, G. and Knoll, P., “The Raman Spectra of Different Ladder Type Poly(p-phenylenes) and Ladder Type Oligo(p-phenylenes),” Macromolecular Symposia, Vol. 181, No. 1, pp. 383388 (2002). doi: 10.1002/1521-3900(200205)181:13.0.CO;2-F
  13. [14] Somitsch, D., Wenzl, F. P., Kreith, J., Pressl, M., Kaindl, R., Scherf, U., Leising, G. and Knoll, P., “The Raman Spectra of Methyl Substituted Ladder Type Poly(pphenylene): Theoretical and Experimental Investigations,” Synthetic Metals, Vol. 138, No. 12, pp. 3942 (2003). doi: 10.1016/S0379-6779(02)01266-3
  14. [15] Knaapila, M., Torkkeli, M., Konôpková D. Haase, Z., Liermann, H.-P., Scherf, U. and Guha, S., “Measuring Structural Inhomogeneity of Conjugated Polymer at High Pressures Up to 30 Gpa,” Macromolecules, Vol. 46, No. 20, pp. 82848288 (2013). doi: 10.1021/ma 401661t
  15. [16] Paudel, K., Moghe, D., Chandrasekhar, M., Yu, P., Ramasesha, S., Scherf, U. and Guha, S., “Pressure Dependence of Singlet and Triplet Excitons in Amorphous Polymer Semiconductors,” Europhysics Letters, Vol. 104, No. 2, pp. 27008 (2013). doi: 10.1209/0295- 5075/104/27008
  16. [17] Guha, S., Graupner, W., Yang, S., Chandrasekhar, M. and Chandrasekhar, H. R., ed. by Glaser, R. and Kaszynski, P., “Approaches to Polar Order,” ACS Symposium Series, American Chemical Society, Washington D.C., Vol. 798, p. 127 (2001).
  17. [18] Mao, H. K., Xu, J. and Bell, P. M., “Calibration of the Ruby Pressure Gauge to 800 kbar Under Quasi-hydrostatic Conditions,” Journal of Geophysical Research: Solid Earth, Vol. 91, No. B5, pp. 46734676 (1986). doi: 10.1029/JB091iB05p04673
  18. [19] Ariu, M., Lidzey, D. G. and Bradley, D. D. C., “Influence of Film Morphology on the Vibrational Spectra of Dioctyl Substituted Polyfluorene (PFO),” Synthetic Metals, Vol. 111112, pp. 607610 (2000). doi: 10. 1016/S0379-6779(99)00320-3
  19. [20] Guha, S., Knaapila, M., Moghe, D., Konôpková, Z., Torkkeli, M., Fritsch, M. and Scherf, U., “Persistence of Nematic Liquid Crystalline Phase in a Polyfluorene-based Organic Semiconductor: A High Pressure Study,” Journal of Polymer Science, Part B: Polymer Physics, Vol. 52, No. 15, pp. 10141023 (2014). doi: 10.1002/polb.23520
  20. [21] Chen, C.-Y., “Raman Scattering of M-LPPP Polymer under Hydrostatic Pressure,” M.S. thesis, Tamkang University, Taiwan (2008).
  21. [22] Baker, K. N., Fratini, A. V., Resch, T. and Knachel, H. C., “Crystal Structures, Phase Transitions and Energy Calculations of Poly(p-phenylene) Oligomers,” Polymer, Vol. 34, No. 8, pp. 15711587 (1993). doi: 10. 1016/0032-3861(93)90313-Y
  22. [23] Carreira, L. A. and Towns, T. G., “Raman Spectra and Barriers to Internal Rotation: Biphenyl and Nitrobenzene,” Journal of Molecular Structure, Vol. 41, No. 1, pp. 19 (1977). doi: 10.1016/0022-2860(77)80034-3
  23. [24] Guha, S., Graupner, W., Resel, R., Chandrasekhar, M., Chandrasekhar, H. R., Glaser, R. and Leising, G., “Tuning Intermolecular Interactions: A Study of the Structural and Vibrational Properties of P-hexaphenyl Under Pressure,” The Journal of Physical Chemistry A, Vol. 105, No. 25, pp. 62036211 (2001). doi: 10. 1021/jp0045540
  24. [25] Chen, Z., Fang, J., Gao, F., Brenner, T. J. K., Banger, K. K., Wang, X., Huck, W. T. S. and Sirringhaus, H., “Enhanced Charge Transport by Incorporating Additional Thiophene Units in the Poly(Fluorene-thienylbenzothiadiazole) Polymer,” Organic Electronics, Vol. 12, No. 3, pp. 461471 (2011). doi: 10.1016/j.orgel. 2010.12.009
  25. [26] Hemley, R. J., “Effects of High Pressure on Molecules,” Annual Review of Physical Chemistry, Vol. 51, pp. 763800 (2000). doi: 10.1146/annurev.physchem. 51.1.763
  26. [27] Zeng, Q. G., Ding, Z. J., Tang, X. D. and Zhang, Z. M., “Pressure Effect on Photoluminescence and Raman Spectra of PPV,” Journal of Luminescence, Vol. 115, No. 12, pp. 3238 (2005). doi: 10.1016/j.jlumin.2005. 02.023
  27. [28] Hsu, C.-H., Chen, C.-Y. and Yang, S.-C., “The Photoluminescence of Ph-LPPP Polymer Under Hydrostatic Pressure,” Journal of Applied Science and Engineering, Vol. 17, No. 3, pp. 253258 (2014). doi: 10.6180/ jase.2014.17.3.05
  28. [29] Hsu, C.-H. and Yang, S.-C., “Photomodulation Spectrum of Phenyl-substituted Ladder-type Poly(paraphenylene) Under Hydrostatic Pressure,” Journal of Polymer Research, Vol. 22, No. 6, p. 105 (2015).
  29. [30] Mulazzi, E., Ripamonti, A., Wéry, J., Dulieu, B. and Lefrant, S., “Theoretical and Experimental Investigation of Absorption and Raman Spectra of Poly(Paraphenylene Vinylene),” Physical Review B, Vol. 60, No. 24, p. 16519 (1999). doi: 10.1103/PhysRevB.60.16519
  30. [31] Wéry, J., Aarab, H., Lefrant, S., Faulques, E., Mulazzi, E. and Perego, R., “Photoexcitations in Composites of Poly(Paraphenylene Vinylene) and Single-Walled Carbon Nanotubes,” Physical Review B, Vol. 67, p. 115202 (2003). doi: 10.1103/PhysRevB.67.115202