Ultrafast-laser-treated poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) electrodes with enhanced conductivity and transparency for semitransparent perovskite solar cells

Abstract

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is an important organic electrode for solution-processed low-cost electronic devices. However, it requires doping and post-solvent treatment to improve its conductivity, and the chemicals used for such treatments may affect the device fabrication process. In this study, we developed a novel route for exploiting ultrafast lasers (femtosecond and picosecond laser) to simultaneously enhance the conductivity and transparency of PEDOT:PSS films and fabricate patterned solution-processed electrodes for electronic devices. The conductivity of the PEDOT:PSS film was improved by three orders of magnitude (from 3.1 to 1024 S·cm^–1), and high transparency of up to 88.5% (average visible transmittance, AVT) was achieved. Raman and depth-profiling X-ray photoelectron spectroscopy revealed that the oxidation level of PEDOT was enhanced, thereby increasing the carrier concentration. The surface PSS content also decreased, which is beneficial to the carrier mobility, resulting in significantly enhanced electrical conductivity. Further, we fabricated semitransparent perovskite solar cells using the as-made PEDOT:PSS as the transparent top electrodes, and a power conversion efficiency of 7.39% was achieved with 22.63% AVT. Thus, the proposed route for synthesizing conductive and transparent electrodes is promising for vacuum and doping-free electronics.

Key words： PEDOT:PSS; ultrafast laser; transparent electrode; ST-PSCs; patterning

Acknowledgments

This study was financially supported by the National Key Research and Development Plan (Grant Nos. 2017YFE0131900, 2019YFE0107200), the National Natural Science Foundation of China (Grant Nos. 52072284, 21875178, 91963209), and Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory (XHD2020-001).

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://dx.doi.org/10.1007/s11705-022-2203-x and is accessible for authorized users.

References

1 Gu Y D, Zhang T, Chen H, Wang F, Pu Y M, Gao C M, Li S B. Mini review on flexible and wearable electronics for monitoring human health information. Nanoscale Research Letters, 2019, 14(1): 263

2 Li R A, Zhang K L, Chen G X. Highly transparent, flexible and conductive CNF/AgNW paper for paper electronics. Materials, 2019, 12(2): 322

3 Zhang L, Song T T, Shi L X, Wen N, Wu Z J, Sun C Y, Jiang D W, Guo Z H. Recent progress for silver nanowires conducting film for flexible electronics. Journal of Nanostructure in Chemistry, 2021, 11(3): 323–341

4 Gao W, Ota H, Kiriya D, Takei K, Javey A. Flexible electronics toward wearable sensing. Accounts of Chemical Research, 2019, 52(3): 523–533

5 Wang Y, Zhu C X, Pfattner R, Yan H P, Jin L H, Chen S C, Molina-Lopez F, Lissel F, Liu J, Rabiah N I, Chen Z, Chung J W, Linder C, Toney M F, Murmann B, Bao Z. A highly stretchable, transparent, and conductive polymer. Science Advances, 2017, 3(3): e1602076

6 Kraft U, Molina-Lopez F, Son D, Bao Z N, Murmann B. Ink development and printing of conducting polymers for intrinsically stretchable interconnects and circuits. Advanced Electronic Materials, 2019, 6(1): 1900681

7 Kavand H, Rahaie M, Koohsorkhi J, Haghighipour N, Bonakdar S. A conductive cell-imprinted substrate based on CNT-PDMS composite. Biotechnology and Applied Biochemistry, 2019, 66(3): 445–453

8 Kim Y U, Kwon N Y, Park S H, Kim C W, Chau H D, Hoang M H, Cho M J, Choi D H. Patterned sandwich-type silver nanowire-based flexible electrode by photolithography. ACS Applied Materials & Interfaces, 2021, 13(51): 61463–61472

9 Tan D C, Jiang C M, Li Q K, Bi S, Song J H. Silver nanowire networks with preparations and applications: a review. Journal of Materials Science Materials in Electronics, 2020, 31(18): 15669–15696

10 Hu H B, Wang S C, Wang S C, Liu G W, Cao T, Long Y. Aligned silver nanowires enabled highly stretchable and transparent electrodes with unusual conductive property. Advanced Functional Materials, 2019, 29(33): 1902922

11 Yang Y, Deng H, Fu Q. Recent progress on PEDOT:PSS based polymer blends and composites for flexible electronics and thermoelectric devices. Materials Chemistry Frontiers, 2020, 4(11): 3130–3152

12 Zheng Y Q, Liu Y X, Zhong D L, Nikzad S, Liu S H, Yu Z, Liu D, Wu H C, Zhu C X, Li J X, Tran H, Tok J B H, Bao Z. Monolithic optical microlithography of high-density elastic circuits. Science, 2021, 373(6550): 88–94

13 Jiang Y Y, Liu T F, Zhou Y H. Recent advances of synthesis, properties, film fabrication methods, modifications of poly(3,4-ethylenedioxythiophene), and applications in solution-processed photovoltaics. Advanced Functional Materials, 2020, 30(51): 2006213

14 Li Z F, Ma G Q, Ge R, Qin F, Dong X Y, Meng W, Liu T F, Tong J H, Jiang F Y, Zhou Y F, Li K, Min X, Huo K, Zhou Y. Free-standing conducting polymer films for high-performance energy devices. Angewandte Chemie International Edition, 2016, 55(3): 979–982

15 Zhang Y K, Ng S W, Lu X, Zheng Z J. Solution-processed transparent electrodes for emerging thin-film solar cells. Chemical Reviews, 2020, 120(4): 2049–2122

16 Lim K, Jung S, Lee S, Heo J, Park J, Kang J W, Kang Y C, Kim D G. The enhancement of electrical and optical properties of PEDOT:PSS using one-step dynamic etching for flexible application. Organic Electronics, 2014, 15(8): 1849–1855

17 Badre C, Marquant L, Alsayed A M, Hough L A. Highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) films using 1-ethyl-3-methylimidazolium tetracyanoborate ionic liquid. Advanced Functional Materials, 2012, 22(13): 2723–2727

18 Hu X T, Huang Z Q, Li F Y, Su M, Huang Z D, Zhao Z P, Cai Z R, Yang X, Meng X C, Li P W, Wang Y, Li M, Chen Y, Song Y. Nacre-inspired crystallization and elastic “brick-and-mortar” structure for a wearable perovskite solar module. Energy & Environmental Science, 2019, 12(3): 979–987

19 Yin L Y, Zhao Z X, Jiang F Y, Li Z F, Xiong S X, Zhou Y H. PEDOT:PSS top electrode prepared by transfer lamination using plastic wrap as the transfer medium for organic solar cells. Organic Electronics, 2014, 15(10): 2593–2598

20 Hu X T, Meng X C, Zhang L, Zhang Y Y, Cai Z R, Huang Z Q, Su M, Wang Y, Li M Z, Li F Y, Yao X, Wang F, Ma W, Chen Y, Song Y. A mechanically robust conducting polymer network electrode for efficient flexible perovskite solar cells. Joule, 2019, 3(9): 2205–2218

21 Hu X T, Chen L, Zhang Y, Hu Q, Yang J L, Chen Y W. Large-scale flexible and highly conductive carbon transparent electrodes via roll-to-roll process and its high performance lab-scale indium tin oxide-free polymer solar cells. Chemistry of Materials, 2014, 26(21): 6293–6302

22 Kim Y H, Sachse C, Machala M L, May C, Muller-Meskamp L, Leo K. Highly conductive PEDOT:PSS electrode with optimized solvent and thermal post-treatment for ITO-free organic solar cells. Advanced Functional Materials, 2011, 21(6): 1076–1081

23 Yeo J S, Yun J M, Kim D Y, Park S, Kim S S, Yoon M H, Kim T W, Na S I. Significant vertical phase separation in solvent-vapor-annealed poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) composite films leading to better conductivity and work function for high-performance indium tin oxide-free optoelectronics. ACS Applied Materials & Interfaces, 2012, 4(5): 2551–2560

24 Kim N, Kee S, Lee S H, Lee B H, Kahng Y H, Jo Y R, Kim B J, Lee K. Highly conductive PEDOT:PSS nanofibrils induced by solution-processed crystallization. Advanced Materials, 2014, 26(14): 2268–2272

25 Yeon C, Yun S J, Kim J, Lim J W. PEDOT:PSS films with greatly enhanced conductivity via nitric acid treatment at room temperature and their application as Pt/TCO-free counter electrodes in dye-sensitized solar cells. Advanced Electronic Materials, 2015, 1(10): 1500121

26 Zhang L, Yang K, Chen R, Zhou Y L, Chen S S, Zheng Y J, Li M, Xu C H, Tang X S, Zang Z G, Sun K. The role of mineral acid doping of PEDOT:PSS and its application in organic photovoltaics. Advanced Electronic Materials, 2020, 6(1): 1900648

27 Zeng M, Wang X J, Ma R J, Zhu W Y, Li Y, Chen Z X, Zhou J W, Li W Q, Liu T, He Z C, Yan H, Huang F, Cao Y. Dopamine semiquinone radical doped PEDOT:PSS: enhanced conductivity, work function and performance in organic solar cells. Advanced Energy Materials, 2020, 10(25): 2000743

28 Zhao F, Chen X F, Yi Z, Qin F, Tang Y J, Yao W T, Zhou Z G, Yi Y G. Study on the solar energy absorption of hybrid solar cells with trapezoid-pyramidal structure based PEDOT:PSS/c-Ge. Solar Energy, 2020, 204: 635–643

29 Sun Z, He Y, Xiong B L, Chen S S, Li M, Zhou Y L, Zheng Y J, Sun K, Yang C. Performance-enhancing approaches for PEDOT:PSS-Si hybrid solar cells. Angewandte Chemie International Edition, 2021, 60(10): 5036–5055

30 Fan X, Nie W Y, Tsai H, Wang N X, Huang H H, Cheng Y J, Wen R J, Ma L J, Yan F, Xia Y G. PEDOT:PSS for flexible and stretchable electronics: modifications, strategies, and applications. Advanced Science, 2019, 6(19): 1900813

31 Mochizuki T, Takigami Y, Kondo T, Okuzaki H. Fabrication of flexible transparent electrodes using PEDOT:PSS and application to resistive touch screen panels. Journal of Applied Polymer Science, 2018, 135(10): 45972

32 Bubnova O, Khan Z U, Malti A, Braun S, Fahlman M, Berggren M, Crispin X. Optimization of the thermoelectric figure of merit in the conducting polymer poly(3,4-ethylenedioxythiophene). Nature Materials, 2011, 10(6): 429–433

33 Manjakkal L, Pullanchiyodan A, Yogeswaran N, Hosseini E S, Dahiya R. A wearable supercapacitor based on conductive PEDOT:PSS-coated cloth and a sweat electrolyte. Advanced Materials, 2020, 32(24): 1907254

34 Liang F C, Chang Y W, Kuo C C, Cho C J, Jiang D H, Jhuang F C, Rwei S P, Borsali R. A mechanically robust silver nanowire-polydimethylsiloxane electrode based on facile transfer printing techniques for wearable displays. Nanoscale, 2019, 11(4): 1520–1530

35 Lee C, Shin S S, Choi J, Kim J, Son J W, Choi M, Shin H H. A micro-patterned electrode/electrolyte interface fabricated by soft-lithography for facile oxygen reduction in solid oxide fuel cells. Journal of Materials Chemistry A: Materials for Energy and Sustainability, 2020, 8(32): 16534–16541

36 Yun C H, Han J W, Kim S, Lim D C, Jung H, Lee S H, Jang J W, Yoo S, Leo K, Kim Y H. Generating semi-metallic conductivity in polymers by laser-driven nanostructural reorganization. Materials Horizons, 2019, 6(10): 2143–2151

37 Barr M C, Rowehl J A, Lunt R R, Xu J, Wang A, Boyce C M, Im S G, Bulovic V, Gleason K K. Direct monolithic integration of organic photovoltaic circuits on unmodified paper. Advanced Materials, 2011, 23(31): 3499–3505

38 Scardaci V, Coull R, Coleman J N. Very thin transparent, conductive carbon nanotube films on flexible substrates. Applied Physics Letters, 2010, 97(2): 023114

39 Sakamoto S, Okumura M, Zhao Z, Furukawa Y. Raman spectral changes of PEDOT-PSS in polymer light-emitting diodes upon operation. Chemical Physics Letters, 2005, 412(4-6): 395–398

40 Wu F L, Li P C, Sun K A, Zhou Y L, Chen W, Fu J H, Li M, Lu S R, Wei D S, Tang X S, Zang Z, Sun L, Liu X, Ouyang J. Conductivity enhancement of PEDOT:PSS via addition of chloroplatinic acid and its mechanism. Advanced Electronic Materials, 2017, 3(7): 1700047

41 Chou T R, Chen S H, Chiang Y T, Chang T T, Lin C W, Chao C Y. Highly conductive PEDOT:PSS film by doping p-toluenesulfonic acid and post-treatment with dimethyl sulfoxide for ITO-free polymer dispersed liquid crystal device. Organic Electronics, 2017, 48(6): 223–229

42 de Kok M M, Buechel M, Vulto S I E, van de Weijer P, Meulenkamp E A, de Winter S H P M, Mank A J G, Vorstenbosch H J M, Weijtens C H L, van Elsbergen V. Modification of PEDOT:PSS as hole injection layer in polymer LEDs. Physica Status Solidi A: Applied Research, 2004, 201(6): 1342–1359

43 Wang X X, Zhang X, Sun L, Lee D, Lee S, Wang M H, Zhao J J, Shao-Horn Y, Dinca M, Palacios T, Gleason K K. High electrical conductivity and carrier mobility in oCVD PEDOT thin films by engineered crystallization and acid treatment. Science Advances, 2018, 4(9): eaat5780

44 Kang S D, Snyder G J. Charge-transport model for conducting polymers. Nature Materials, 2017, 16(2): 252–257

45 Jakobsson F L E, Crispin X, Lindell L, Kanciurzewska A, Fahlman M, Salaneck W R, Berggren M. Towards all-plastic flexible light emitting diodes. Chemical Physics Letters, 2006, 433(1-3): 110–114

46 Zotti G, Zecchin S, Schiavon G, Louwet F, Groenendaal L, Crispin X, Osikowicz W, Salaneck W, Fahlman M. Electrochemical and XPS studies toward the role of monomeric and polymeric sulfonate counterions in the synthesis, composition, and properties of poly(3,4-ethylenedioxythiophene). Macromolecules, 2003, 36(9): 3337–3344

47 Montibon E, Järnström L, Lestelius M. Characterization of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) adsorption on cellulosic materials. Cellulose (London, England), 2009, 16(5): 807–815

48 Zhang Y K, Wu Z W, Li P, Ono L K, Qi Y B, Zhou J X, Shen H, Surya C, Zheng Z J. Fully solution-processed TCO-free semitransparent perovskite solar cells for tandem and flexible applications. Advanced Energy Materials, 2018, 8(1): 1701569

49 Hosseini E, Ozhukil Kollath V, Karan K. The key mechanism of conductivity in PEDOT:PSS thin films exposed by anomalous conduction behaviour upon solvent-doping and sulfuric acid post-treatment. Journal of Materials Chemistry C: Materials for Optical and Electronic Devices, 2020, 8(12): 3982–3990

50 Huseynova G, Hyun Kim Y, Lee J H, Lee J. Rising advancements in the application of PEDOT:PSS as a prosperous transparent and flexible electrode material for solution-processed organic electronics. Journal of Information Display, 2020, 21(2): 71–91