Abstract
Conjugated polymers of BTTP and BTTP–CN comprising thiophene and benzothiadiazole substituents were subjected under chemical doping process. The polymers were doped with different Lewis acids such as AlCl3, H3BO3, BF3, Cu(II), Fe(II), HCl and I2. The doped and undoped polymers have been analyzed with the aid of FTIR, UV–Vis, fluorescence spectrometer, electrochemical conductivity and cyclic voltammetry. Upon doping, the absorption maximum of the polymers (403 and 397 nm) were dramatically shifted and emission wavelength of BTTP and BTTP–CN was red shifted due to chemical interaction among dopants. The electrochemical band gap of undoped polymers BTTP and BTTP–CN has been measured as 1.9 and 1.6 eV and conductivity was measured as 3.62 and 1.46 × 10–5 Ω−1 cm−1, respectively. After doping with Lewis acids, band gap was reduced and conductivity was increased. The reactivity of the polymers with AlCl3, BF3, and HCl dopants produced low band gap, high conductivity up to 0.79 eV, 5.98 × 10–5 Ω−1 for BTTP and 1.0 eV, 4.43 × 10–5 Ω−1 for BTTP–CN, respectively. Introduction of dopants to the conjugated polymers opens up the opportunity to increase conjugation, Turn off/on fluorescence and shifting of energy levels in solar cell applications.
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References
Namsheer K, Rout CS (2021) Conducting polymers: a comprehensive review on recent advances in synthesis, properties and applications. RSC Adv 11:5659–5697
MacDiarmid AG, Mammone RJ, Kaner RB, Porter SJ, Pethig R, Heeger AJ, Rosseinsky DR (1985) The concept of ‘doping’ of conducting polymers: the role of reduction potentials. Phil Trans R Soc A 314:3–15
MacDiarmid AG (2001) “Synthetic Metals”: a novel role for organic polymers (Nobel Lecture) Copyright((c)) The Nobel Foundation 2001. We thank the Nobel Foundation, Stockholm, for permission to print this lecture. Angew Chem Int Ed Engl 40:2581–2590
Park SH, Roy A, Beaupre S, Cho S, Coates N, Moon JS, Moses D, Leclerc M, Lee K, Heeger AJ (2009) Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nat Photonics 3:297–303
Bienkowski K, Kulszewicz-Bajer I, Genoud F, Oddou JL, Pron A (2003) Conjugated polymers doped with Lewis acids. Synth Met 135–136:159–160
Kulszewicz-Bajer I, Pron A, Abramowicz J, Jeandey C, Oddou J-L, Sobczak JW (1999) Lewis acid doped polyaniline: preparation and spectroscopic characterization. Chem Mater 11:552–556
Facchetti A (2011) π-Conjugated polymers for organic electronics and photovoltaic cell applications. Chem Mater 23:733–758
Cai WZ, Gong X, Cao Y (2010) Polymer solar cells: recent development and possible routes for improvement in the performance. Sol Energy Mater Sol Cells 94:114–127
Wang M, Hu X, Liu P, Li W, Gong X, Huang F, Cao Y (2011) Donor–acceptor conjugated polymer based on Naphtho[1,2-c:5,6-c]bis[1,2,5]thiadiazole for high-performance polymer solar cells. J Am Chem Soc 133:9638–9641
Balan A, Baran D, Toppare L (2011) Benzotriazole containing conjugated polymers for multipurpose organic electronic applications. Polym Chem 2:1029–1043
Jiang H, Taranekar P, Reynolds JR, Schanze KS (2009) Conjugated polyelectrolytes: synthesis, photophysics, and applications. Angew Chem Int Ed 48:4300–4316
Sun H, Guo X, Facchetti A (2020) High-performance n-type polymer semiconductors: applications, recent development, and challenges. Chem 6:1310–1326
Mahesh K, Karpagam S (2017) Thiophene–Thiazole functionalized oligomers-excellent fluorescent sensing and selective probe for copper and iron ion. Sens Actuators B Chem B 251:9–20
Zhang X, Steckler TT, Dasari RR, Ohira S, Potscavage WJ, Tiwari SP, Coppee S, Ellinger S, Barlow S, Bredas JL, Kippelen B, Reynolds JR, Marder SR (2010) Dithienopyrrole-based donor–acceptor copolymers: low band-gap materials for charge transport, photovoltaics and electrochromism. J Mater Chem 20:123–134
Xu S, Liu Y, Li J, Wang Y, Cao S (2010) Synthesis and characterization of low-band-gap conjugated polymers containing phenothiazine and benzo-2,1,3-thia-/seleno-diazole. Polym Adv Technol 21:663–668
Poverenov E, Zamoshchik N, Patra A, Ridelman Y, Bendikov M (2014) Unusual doping of donor−acceptor-type conjugated polymers using Lewis acids. J Am Chem Soc 136:5138–5149
Peet J, Kim JY, Coates NE, Ma WL, Moses D, Heeger AJ, Bazan GC (2007) Efficiency enhancement in low-bandgap polymer solar cells by processing with alkane dithiols. Nat Mater 6:497–500
Welch GC, Coffin R, Peet J, Bazan GC (2009) Band gap control in conjugated oligomers via Lewis acids. J Am Chem Soc 131:10802–10803
Welch GC, Bazan GC (2011) Lewis acid adducts of narrow band gap conjugated polymers. J Am Chem Soc 133:4632–4644
Zalar P, Henson ZB, Welch GC, Bazan GC, Nguyen TQ (2012) Color tuning in polymer light-emitting diodes with Lewis acids. Angew Chem Int Ed 51:7495–7498
Mahesh K, Karpagam S, Putnin T, Le H, Bui TT, Ounnunkad K, Goubard F (2019) Role of cyano substituents on thiophene vinylene benzothiadiazole conjugated polymers and application as hole transporting materials in perovskite solar cells. J Photochem Photobiol A Chem 371:238–247
Olgun U, Gulfen M (2014) M, Effects of different dopants on the band gap and electrical conductivity of the poly (phenylene-thiazolo [5, 4-d] thiazole) copolymer. RSC Adv 4:25165–25171
Yurash B, Cao DX, Brus VV, Leifert D, Wang M, Dixon A, Seifrid M, Mansour AE, Lungwitz D, Liu T, Santiago PJ, Graham KR, Koch N, Bazan GC, Nguyen T-Q (2019) Towards understanding the doping mechanism of organic semiconductors by Lewis acids. Nat Mater 18:1327–1334
Olgun U, Gulfen M (2014) Synthesis of fluorescence poly (phenylenethiazolo [5, 4-d] thiazole) copolymer dye: spectroscopy, cyclic voltammetry and thermal analysis. Dyes Pigments 102:189–195
Zhou H, Yang L, You W (2012) Rational design of high performance conjugated polymers for organic solar cells. Macromolecules 45:607–632
Qian X, Gu N, Cheng Z, Yang X, Wang E, Dong S (2001) Methods to study the ionic conductivity of polymeric electrolytes using ac impedance spectroscopy. J Solid State Electrochem 6:8–15
Sathiyan G, Thangamuthu R, Sakthivel P (2016) Synthesis of carbazole-based copolymers containing carbazole-thiazolo [5,4-d] thiazole groups with different dopants and their fluorescence and electrical conductivity applications. RSC Adv 6:69196–69205
Ye G et al (2021) Controlling n-type molecular doping via regiochemistry and polarity of pendant groups on low band gap donor-acceptor copolymers. Macromolecules 54(8):3886–3896
Marques PS, Londi G, Yurash B, Nguyen T-Q, Barlow S, Marder SR, Beljonne D (2021) Understanding how Lewis acids dope organic semiconductors: a “complex” story. Chem Sci 12:7012
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The authors thank VIT for providing ‘VIT SEED GRANT’ for carrying out this research work and grateful to DST/VIT-FIST for providing instrumental facilities.
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Karpagam, S., Anupriya, P. & Supraja, N. Effects of chemical dopants on the luminescence, bandgap and electrochemical conductivity of the thiophene-based benzothiadiazole-conjugated polymers. Polym. Bull. 80, 757–771 (2023). https://doi.org/10.1007/s00289-021-04050-9
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DOI: https://doi.org/10.1007/s00289-021-04050-9