THERMAL ANNEALING EFFECTS ON SURFACE MORPHOLOGY AND ELECTRON DYNAMICS IN PSIF-DBT:PCBM BLENDS
DOI:
https://doi.org/10.17563/rbav.v45i1.1280Keywords:
PSiF-DBT:PCBM, X-ray absorption spectroscopy, Resonant Auger spectroscopy, Electron delocalization, Thermal annealingAbstract
We investigated the impact of thermal annealing on the electronic properties, order and transport characteristic of PSiF-DBT:PCBM bulk-heterojunction thin films using sulfur K-edge X-ray absorption spectroscopy (XAS) together with resonant Auger spectroscopy (RAS). PSiF-DBT:PCBM thin films were produced and thermally annealed at two distinct temperatures: 100 and 200°C. RAS experiments, combined with the core-hole clock methodology, were used to extract electron delocalization times by analyzing resonant and normal Auger decay channels following sulfur 1s excitation. The spectroscopic data yield element-specific information on the electronic states of PSiF-DBT and on interfacial charge-transfer processes in PSiF-DBT:PCBM blends as a function of annealing temperature, which was also investigated by atomic force microscopy. This methodology enables direct evaluation of thermal-treatment-induced changes in electronic coupling and charge-transport pathways in silicon-containing donor–acceptor organic semiconductor blends.
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1. Sun Y, Wang L, Guo C, Xiao J, Liu C, Chen C, Xia W, Gan Z, Cheng J, Zhou J, Chen Z, Zhou J, Liu D, Wang T, Li W. π extended nonfullerene acceptor for compressed molecular packing in organic solar cells to achieve over 20% efficiency. J Am Chem Soc. 2024;146(17):12011-9. https://doi.org/10.1021/jacs.4c01503
2. Rafique S, Abdullah SM, Sulaiman K, Iwamoto M. Fundamentals of bulk heterojunction organic solar cells: an overview of stability/degradation issues and strategies for improvement. Renew Sustain Energy Rev. 2018;84:43-53. https://doi.org/10.1016/j.rser.2017.12.008
3. Kumar S, Sharma A, Pathak D, Nunzi JM. Bulk heterojunction solar cells. In: Kumar V, Pathak D, Sharma DP, Nunzi JM, editors. Solar Cell Engineering: advanced materials and technologies for photovoltaics. Elsevier; 2026. p. 203-28. https://doi.org/10.1016/B978-0-443-29250-7.00012-8
4. Bassi MDJ, Benatto L, Wouk L, Holakoei S, Oliveira CK, Rocco MLM, Roman LS. Correlation between structural and optical characteristics of conjugated copolymers differing by a Si bridge atom. Phys Chem Chem Phys. 2020;22(35):19923-31. https://doi.org/10.1039/D0CP02520H
5. He Y, Li N, Heumüller T, Wortmann J, Hanisch B, Aubele A, Lucas S, Feng G, Jiang X, Li W, Bäuerle P, Brabec CJ. Industrial viability of single-component organic solar cells. Joule. 2022;6(6):1160-71. https://doi.org/10.1016/j.joule.2022.05.008
6. Majhi J, Ghosh S, Priya K, Sharma S, Bandyopadhyay A. A critical review on the progress of emerging active and substrate materials for organic solar cells and device level fabrication techniques by solution process method. Next Mater. 2025;8:100595. https://doi.org/10.1016/j.nxmate.2025.100595
7. Marchiori CFN, Yamamoto NAD, Matos CF, Kujala J, Macedo AG, Tuomisto F, Zarbin AJG, Koehler M, Roman LS. Annealing effect on donor-acceptor interface and its impact on the performance of organic photovoltaic devices based on PSiF-DBT copolymer and C60. Appl Phys Lett. 2015;106:133301. https://doi.org/10.1063/1.4916515
8. Marchiori CFN, Garcia-Basabe Y, de A Ribeiro F, Koehler M, Roman LS, Rocco MLM. Thermally induced anchoring of fullerene in copolymers with Si-bridging atom: Spectroscopic evidences. Spectrochim Acta A Mol Biomol Spectrosc. 2017;171:376–82. https://doi.org/10.1016/j.saa.2016.08.010
9. Zhou H, Yang L, You W. Rational design of high performance conjugated polymers for organic solar cells. Macromolecules. 2012;45(2):607-32. https://doi.org/10.1021/ma201648t
10. Bulavko G. Organic photovoltaics: A journey through time, advancements, and future opportunities. Hist Sci Technol. 2024;14(1):10-32. https://doi.org/10.32703/2415-7422-2024-14-1-10-32
11. Shmakov SN, Jia Y, Pinkhassik E. Selectively initiated ship-in-a-bottle assembly of yolk-shell nanostructures. Chem Mater. 2014;26(2):1126-32. https://doi.org/10.1021/cm403442k
12. Chen D, Nakahara A, Wei D, Nordlund D, Russell TP. P3HT/PCBM bulk heterojunction organic photovoltaics: correlating efficiency and morphology. Nano Lett. 2011;11(2):561-7. https://doi.org/10.1021/nl103482n
13. Sahoo S, Barah D, Kumar SD, Xavier N, Dutta S, Ray D, Bhattacharyya J. The nature of excitons in PPDT2FBT:PCBM solar cells: role played by PCBM. J Phys D Appl Phys. 2022;55:455103. https://doi.org/10.1088/1361-6463/ac8819
14. Mikroyannidis JA, Kabanakis AN, Sharma SS, Sharma GD. A simple and effective modification of PCBM for use as an electron acceptor in efficient bulk heterojunction solar cells. Adv Funct Mater. 2011;21(4):746-55. https://doi.org/10.1002/adfm.201001807
15. Marchiori CFN, Garcia-Basabe Y, Matos CF, Koehler M, Roman LS, Rocco MLM. Thermal annealing effects on the morphology and electronic structure of PSiF-DBT:PCBM thin films. Thin Solid Films. 2016;618:150-6.
16. Garcia-Basabe Y, Marchiori CFN, Borges BGAL, Yamamoto NAD, Macedo AG, Koehler M, Roman LS, Rocco MLM. Electronic structure, molecular orientation, charge transfer dynamics and solar cell performance in donor/acceptor copolymers and fullerene: experimental and theoretical approaches. J Appl Phys. 2014;115:134901. https://doi.org/10.1063/1.4870470
17. Garcia-Basabe Y, Marchiori CFN, Moura CEV, Rocha AB, Roman LS, Rocco MLM. Charge transfer dynamics and molecular orientation probed by core electron spectroscopies on thermal-annealed polysilafluorene derivative: experimental and theoretical approaches. J Phys Chem C. 2014;118(41):23863-73. https://doi.org/10.1021/jp508010u
18. Ishikawa D. Recent topics in X-ray absorption spectroscopy: integrating theory, instrumentation, and applications. Anal Sci. 2025;41(10):1573-4. https://doi.org/10.1007/s44211-025-00840-7
19. Yano J, Yachandra VK. X-ray absorption spectroscopy. Photosynth Res. 2009;102(2-3):241-54. https://doi.org/10.1007/s11120-009-9473-8
20. Menzel D. Ultrafast charge transfer at surfaces accessed by core electron spectroscopies. Chem Soc Rev. 2008; 37(10): 2212-23. https://doi.org/10.1039/B719546J
21. Borges BGAL, Roman LS, Rocco MLM. Femtosecond and attosecond electron transfer dynamics of semiconductors probed by the core-hole clock spectroscopy. Top Catal. 2019;62:1004-10. https://doi.org/10.1007/s11244-019-01189-8
22. Bassi MDJ, Benatto L, Wouk L, Holakoei S, Oliveira CK, Rocco MLM, Roman LS. Correlation between structural and optical characteristics of conjugated copolymers differing by a Si bridge atom. Phys Chem Chem Phys. 2020; 22(35): 19923-31. https://doi.org/10.1039/D0CP02520H
23. Benatto L, Moraes CAM, Bassi MJ, Wouk L, Roman LS, Koehler M. Kinetic modeling of the electric field dependent exciton quenching at the donor-acceptor interface. J Phys Chem C. 2021;125(8):4436-48. https://doi.org/10.1021/acs.jpcc.0c11458
24. Aygül U, Batchelor D, Dettinger U, Yilmaz S, Allard S, Scherf U, Peisert H, Chassé T. Molecular orientation in polymer films for organic solar cells studied by NEXAFS. J Phys Chem C. 2012;116(7):4870-4. https://doi.org/10.1021/jp205653n
25. Campbell JL, Papp T. Widths of the atomic K-N7 levels. At Data Nucl Data Tables. 2001;77(1):1-56. https://doi.org/10.1006/adnd.2000.0848
26. Garcia-Basabe Y, Borges BGAL, Silva DC, Macedo AG, Micaroni L, Roman LS, Rocco MLM. The interplay of electronic structure, molecular orientation and charge transport in organic semiconductors: poly(thiophene) and poly(bithiophene). Org Electron. 2013;14(11):2980-6. https://doi.org/10.1016/j.orgel.2013.08.022
27. Borges BGAL, Veiga AG, Tzounis L, Laskarakis A, Logothetidis S, Rocco MLM. Molecular orientation and ultrafast charge transfer dynamics studies on the P3HT:PCBM blend. J Phys Chem C. 2016;120(43):25078-82. https://doi.org/10.1021/acs.jpcc.6b08056
28. Misael WA, Péan EV, Borges BGAL, Mello GC, Wouk L, Davies ML, Roman LS, Rocco MLM. Molecular orientation and femtosecond electron transfer dynamics in halogenated and nonhalogenated, eco-friendly processed PTB7-Th, ITIC, PTB7-Th:ITIC, and PTB7-Th:PCBM films. J Phys Chem C. 2022;126(26):10807-17. https://doi.org/10.1021/acs.jpcc.2c01298
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Copyright (c) 2026 Bruno Gabriel Alves Leite Borges, Maiara de Jesus Bassi, Lucimara Stolz Roman, Maria Luiza Rocco Duarte Pereira
This work is licensed under a Creative Commons Attribution 4.0 International License.
