Efficient p-i-n structured perovskite solar cells employing low-cost and highly reproducible oligomers as hole transporting materials

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  • ReceivedDec 24, 2018
  • AcceptedMar 1, 2019
  • PublishedMar 28, 2019


The development of p-i-n structured perovskite solar cells (PSCs) requires more extensive explorations on seeking efficient, low cost and stable hole transporting materials (HTMs). Small molecular HTMs are superior to polymeric ones in terms of synthetic reproducibility as well as purity. However, thin films composed of small molecules are usually labile during the solution-based perovskite deposition. Herein, we propose a molecular engineering strategy of incorporating oligothiophene as conjugation bridge to develop robust oligomer HTMs for p-i-n type PSCs. Upon increasing the oligothiophene chain length from α-bithiophene to α-quaterthiophene and α-hexathiophene, their HOMO energy levels remain unchanged, but their solubility in common organic solvents decreased remarkably, thus greatly enhancing their tolerance to the perovskite deposition. The rational design of oligothiophene chain length can effectively tune their optoelectronic properties as well as thin film stability under polar solvent soaking. The best performance is achieved by an α-quaterthiophene based HTM (QT), showing a high efficiency of 17.69% with fill factor of 0.81, which are comparable to those of a commercially available benchmark polymer HTM (poly[bis(4-phenyl)(2,4-dimethylphenyl) amine], PTAA) based devices fabricated under the same conditions. Our developed oligomer system not only provides the definite molecular structures like small molecule-type HTMs, but also exhibits the excellent film-forming like polymer-type HTMs, thus achieving the well-balanced parameters among solvent tolerance, thin film conductivity, and interfacial charge transfer efficiency, especially building up a platform to develop low cost and reproducible efficient HTMs in p-i-n structured perovskite solar cells.

Funded by

the National Natural Science Foundation of China(21822504,21706070,21421004,21636002)

Shanghai Science and Technology Committee(17ZR1407400,17520750100)

China Association of Science and Technology(2017QNRC001)

Eastern Scholar(TP2016018)

and the Fundamental Research Funds for the Central Universities(WJ1714007)


This work was supported by the National Natural Science Foundation of China (21822504, 21706070, 21421004, 21636002), Shanghai Science and Technology Committee (17ZR1407400, 17520750100), China Association of Science and Technology (2017QNRC001), Eastern Scholar (TP2016018), and the Fundamental Research Funds for the Central Universities (WJ1714007).

Interest statement

The authors declare that they have no conflict of interest.


The supporting information is available online at http://chem.scichina.com and http://link.springer.com/journal/11426. The supporting materials are published as submitted, without typesetting or editing. The responsibility for scientific accuracy and content remains entirely with the authors.


[1] Kojima A, Teshima K, Shirai Y, Miyasaka T. J Am Chem Soc, 2009, 131: 6050-6051 CrossRef PubMed Google Scholar

[2] Rong Y, Hu Y, Mei A, Tan H, Saidaminov MI, Seok SI, McGehee MD, Sargent EH, Han H. Science, 2018, 361: eaat8235 CrossRef PubMed Google Scholar

[3] Liu D, Zhou W, Tang H, Fu P, Ning Z. Sci China Chem, 2018, 61: 1278-1284 CrossRef Google Scholar

[4] Xiao J, Shi J, Li D, Meng Q. Sci China Chem, 2015, 58: 221-238 CrossRef Google Scholar

[5] Seo J, Noh JH, Seok SI. Acc Chem Res, 2016, 49: 562-572 CrossRef PubMed Google Scholar

[6] Kim HS, Lee CR, Im JH, Lee KB, Moehl T, Marchioro A, Moon SJ, Humphry-Baker R, Yum JH, Moser JE, Grätzel M, Park NG. Sci Rep, 2012, 2: 591 CrossRef PubMed ADS Google Scholar

[7] Tan H, Jain A, Voznyy O, Lan X, García de Arquer FP, Fan JZ, Quintero-Bermudez R, Yuan M, Zhang B, Zhao Y, Fan F, Li P, Quan LN, Zhao Y, Lu ZH, Yang Z, Hoogland S, Sargent EH. Science, 2017, 355: 722-726 CrossRef PubMed ADS Google Scholar

[8] Bi D, Tress W, Dar MI, Gao P, Luo J, Renevier C, Schenk K, Abate A, Giordano F, Correa Baena JP, Decoppet JD, Zakeeruddin SM, Nazeeruddin MK, Gra tzel M, Hagfeldt A. Sci Adv, 2016, 2: e1501170 CrossRef PubMed ADS Google Scholar

[9] Jiang Q, Zhang L, Wang H, Yang X, Meng J, Liu H, Yin Z, Wu J, Zhang X, You J. Nat Energy, 2016, 2: 16177 CrossRef ADS Google Scholar

[10] Zheng G, Zhu C, Ma J, Zhang X, Tang G, Li R, Chen Y, Li L, Hu J, Hong J, Chen Q, Gao X, Zhou H. Nat Commun, 2018, 9: 2793 CrossRef PubMed ADS Google Scholar

[11] Jiang X, Yu Z, Lai J, Zhang Y, Lei N, Wang D, Sun L. Sci China Chem, 2017, 60: 423-430 CrossRef Google Scholar

[12] Jeng JY, Chiang YF, Lee MH, Peng SR, Guo TF, Chen P, Wen TC. Adv Mater, 2013, 25: 3727-3732 CrossRef PubMed Google Scholar

[13] Meng L, You J, Guo TF, Yang Y. Acc Chem Res, 2016, 49: 155-165 CrossRef PubMed Google Scholar

[14] Chen W, Wu Y, Yue Y, Liu J, Zhang W, Yang X, Chen H, Bi E, Ashraful I, Grätzel M, Han L. Science, 2015, 350: 944-948 CrossRef PubMed Google Scholar

[15] Luo D, Yang W, Wang Z, Sadhanala A, Hu Q, Su R, Shivanna R, Trindade GF, Watts JF, Xu Z, Liu T, Chen K, Ye F, Wu P, Zhao L, Wu J, Tu Y, Zhang Y, Yang X, Zhang W, Friend RH, Gong Q, Snaith HJ, Zhu R. Science, 2018, 360: 1442-1446 CrossRef PubMed ADS Google Scholar

[16] Wu Y, Yang X, Chen W, Yue Y, Cai M, Xie F, Bi E, Islam A, Han L. Nat Energy, 2016, 1: 16148 CrossRef ADS Google Scholar

[17] Yan W, Ye S, Li Y, Sun W, Rao H, Liu Z, Bian Z, Huang C. Adv Energy Mater, 2016, 6: 1600474 CrossRef Google Scholar

[18] Liu X, Huang P, Dong Q, Wang Z, Zhang K, Yu H, Lei M, Zhou Y, Song B, Li Y. Sci China Chem, 2017, 60: 136-143 CrossRef Google Scholar

[19] Wang Q, Chueh CC, Eslamian M, Jen AKY. ACS Appl Mater Interfaces, 2016, 8: 32068-32076 CrossRef Google Scholar

[20] Huang J, Wang KX, Chang JJ, Jiang YY, Xiao QS, Li Y. J Mater Chem A, 2017, 5: 13817-13822 CrossRef Google Scholar

[21] Bi C, Wang Q, Shao Y, Yuan Y, Xiao Z, Huang J. Nat Commun, 2015, 6: 7747 CrossRef PubMed ADS Google Scholar

[22] Nie W, Tsai H, Blancon JC, Liu F, Stoumpos CC, Traore B, Kepenekian M, Durand O, Katan C, Tretiak S, Crochet J, Ajayan PM, Kanatzidis MG, Even J, Mohite AD. Adv Mater, 2017, 30: 1703879 CrossRef PubMed Google Scholar

[23] Hou F, Su Z, Jin F, Yan X, Wang L, Zhao H, Zhu J, Chu B, Li W. Nanoscale, 2015, 7: 9427-9432 CrossRef PubMed ADS Google Scholar

[24] Wang Q, Bi C, Huang J. Nano Energy, 2015, 15: 275-280 CrossRef Google Scholar

[25] Tong T, Tan C, Keller T, Li B, Zheng C, Scherf U, Gao D, Huang W. Macromolecules, 2018, 51: 7407-7416 CrossRef ADS Google Scholar

[26] Matsui T, Petrikyte I, Malinauskas T, Domanski K, Daskeviciene M, Steponaitis M, Gratia P, Tress W, Correa-Baena JP, Abate A, Hagfeldt A, Grätzel M, Nazeeruddin MK, Getautis V, Saliba M. ChemSusChem, 2016, 9: 2567-2571 CrossRef PubMed Google Scholar

[27] Yang L, Cai F, Yan Y, Li J, Liu D, Pearson AJ, Wang T. Adv Funct Mater, 2017, 27: 1702613 CrossRef Google Scholar

[28] Huang C, Fu W, Li CZ, Zhang Z, Qiu W, Shi M, Heremans P, Jen AKY, Chen H. J Am Chem Soc, 2016, 138: 2528-2531 CrossRef PubMed Google Scholar

[29] Shang R, Zhou Z, Nishioka H, Halim H, Furukawa S, Takei I, Ninomiya N, Nakamura E. J Am Chem Soc, 2018, 140: 5018-5022 CrossRef PubMed Google Scholar

[30] Magomedov A, Al-Ashouri A, Kasparavičius E, Strazdaite S, Niaura G, Jošt M, Malinauskas T, Albrecht S, Getautis V. Adv Energy Mater, 2018, 8: 1801892 CrossRef Google Scholar

[31] Calió L, Kazim S, Grätzel M, Ahmad S. Angew Chem Int Ed, 2016, 55: 14522-14545 CrossRef PubMed Google Scholar

[32] Kan B, Li M, Zhang Q, Liu F, Wan X, Wang Y, Ni W, Long G, Yang X, Feng H, Zuo Y, Zhang M, Huang F, Cao Y, Russell TP, Chen Y. J Am Chem Soc, 2015, 137: 3886-3893 CrossRef PubMed Google Scholar

[33] Hu W, Zhang Z, Cui J, Shen W, Li M, He R. Nanoscale, 2017, 9: 12916-12924 CrossRef PubMed Google Scholar

[34] Liu B, Chai Q, Zhang W, Wu W, Tian H, Zhu WH. Green Energy Environ, 2016, 7: 6068-6075 CrossRef Google Scholar

[35] Li W, Shi W, Wu Z, Wang J, Wu M, Zhu WH. Green Energy Environ, 2017, 2: 428-435 CrossRef Google Scholar

[36] Yan W, Li Y, Li Y, Ye S, Liu Z, Wang S, Bian Z, Huang C. Nano Res, 2015, 8: 2474-2480 CrossRef Google Scholar

[37] Paek S, Zimmermann I, Gao P, Gratia P, Rakstys K, Grancini G, Nazeeruddin MK, Rub MA, Kosa SA, Alamry KA, Asiri AM. Chem Sci, 2016, 7: 6068-6075 CrossRef PubMed Google Scholar

[38] Yan W, Li Y, Li Y, Ye S, Liu Z, Wang S, Bian Z, Huang C. Nano Energy, 2015, 16: 428-437 CrossRef Google Scholar

[39] Xu B, Gabrielsson E, Safdari M, Cheng M, Hua Y, Tian H, Gardner JM, Kloo L, Sun L. Adv Energy Mater, 2015, 5: 1402340 CrossRef Google Scholar

[40] Liu F, Zhu J, Wei J, Li Y, Lv M, Yang S, Zhang B, Yao J, Dai S. Appl Phys Lett, 2014, 104: 253508 CrossRef ADS Google Scholar

[41] Kim HD, Ohkita H. Sol RRL, 2017, 1: 1700027 CrossRef Google Scholar

[42] Xiao Z, Bi C, Shao Y, Dong Q, Wang Q, Yuan Y, Wang C, Gao Y, Huang J. Energy Environ Sci, 2014, 7: 2619-2623 CrossRef Google Scholar

[43] Stoumpos CC, Malliakas CD, Kanatzidis MG. Inorg Chem, 2013, 52: 9019-9038 CrossRef PubMed Google Scholar

[44] Stranks SD, Eperon GE, Grancini G, Menelaou C, Alcocer MJP, Leijtens T, Herz LM, Petrozza A, Snaith HJ. Science, 2013, 342: 341-344 CrossRef PubMed ADS Google Scholar

[45] Shi D, Adinolfi V, Comin R, Yuan M, Alarousu E, Buin A, Chen Y, Hoogland S, Rothenberger A, Katsiev K, Losovyj Y, Zhang X, Dowben PA, Mohammed OF, Sargent EH, Bakr OM. Science, 2015, 347: 519-522 CrossRef PubMed ADS Google Scholar

[46] Zhang W, Smith J, Hamilton R, Heeney M, Kirkpatrick J, Song K, Watkins SE, Anthopoulos T, McCulloch I. J Am Chem Soc, 2009, 131: 10814-10815 CrossRef PubMed Google Scholar

  • Figure 1

    Device configuration of the p-i-n structured perovskite solar cell and molecular structure of oligomer HTMs named as BT, QT and HT in this work (color online).

  • Figure 2

    UV-visible absorption spectra (a) and emission spectra (b) of BT, QT and HT in dichloromethane. (c) CV spectra of BT, QT and HT in dichloromethane, and (d) energy-level diagram in perovskite solar cells with different HTMs (color online).

  • Figure 3

    (a) UV-vis transmittance of HTM films on ITO substrate. (b) AFM height image of BT film on ITO (scale bar is 1 μm). (c) Contact angle of water on different HTM films. (d) Conductivity measurement of HTMs with the device structure of ITO/HTM/Ag (color online).

  • Figure 4

    Top-view SEM of MAPbI3 grown on BT- (a, d), QT- (b, e), and HT- (c, f) covered ITO substrates. Scale bars: 20 μm in (a, b, c) and 1 μm in (d, e, f).

  • Figure 5

    UV-visible absorption (a) and XRD (b) spectra of MAPbI3 films formed on different HTM layers. (c) The steady state PL spectra of glass/perovskite and glass/perovskite/HTM, and (d) the corresponding time-resolved PL spectra measured at the peak emission wavelength of 760 nm. G, and P means glass and perovskite, respectively (color online).

  • Figure 6

    (a) Cross-sectional SEM image of the p-i-n structured PSCs. J-V curves (b) and EQE (c) of the devices based on different HTMs. (d) The reproducibility of different batches devices using PTAA and QT as HTMs (color online).

  • Table 1   Photovoltaic parameters of best performance PSCs with and without HTMs

    VOC (V)

    JSC (mA cm−1)


    PCE (%)





















  • Table 2   Statistics of device performance in different batches based on PTAA and

    The average efficiency (%)

    The standard deviation

























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