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Tunable exciton binding energy in 2D hybrid layered perovskites through donor–acceptor interactions within the organic layer


The strength of electrostatic interactions within semiconductors strongly affects their performance in optoelectronic devices. An important target is the tuning of a material’s exciton binding energy—the energy binding an electron–hole pair through the electrostatic Coulomb force—independent of its electronic band gap. Here, we report on the doping of a family of two-dimensional hybrid perovskites, in which inorganic lead halide sheets alternate with naphthalene-based organic layers, with tetrachloro-1,2-benzoquinone (TCBQ). For four out of seven n = 1 perovskites, the incorporation of the electron-accepting TCBQ dopant into the organic sublattice containing the electron-donating naphthalene species enabled the tuning of the materials’ 1s exciton binding energy. The naphthalene–TCBQ electron donor–acceptor interactions increased the electrostatic screening of the exciton, in turn lowering its binding energy relative to the undoped perovskite—by almost 50% in one system. Structural and optical characterization showed that the inorganic lattice is not significantly perturbed even though the layer-to-layer spacing increases upon molecular dopant incorporation.

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Fig. 1: Molecular doping approach to tune the exciton binding energy through incorporation of a TCBQ dopant into the Nap organic lattice of a layered perovskite.
Fig. 2: Absorption spectra of perovskite precursors showing a charge transfer absorption band and description of spin-coating formulations.
Fig. 3: Characterization of perovskite 2 films showing a progressive increase in lattice spacing with increasing molecular concentration of the TCBQ dopant.
Fig. 4: Progression of the optical properties of perovskites with TCBQ dopant.
Fig. 5: Temperature-dependent ultraviolet–visible absorption spectra of thin films of perovskite 2.
Fig. 6: Changes in binding energy (Eb) for perovskite 2 thin films with increasing TCBQ.
Fig. 7: Description of the different TCBQ incorporation regimes observed when TCBQ is formulated with perovskites 17.

Data availability

The data that support this work are available in the manuscript and its Supplementary Information files. Further raw data are available from the corresponding authors upon request. X-ray crystallographic data have been deposited at the Cambridge Crystallographic Data Centre ( with CCDC references 1934873 (3), 1934874 (4), 1934872 (5), 1934871 (6), 1934875 (7) and 1934876 (8). A copy of the data can be obtained free of charge via

Code availability

The custom MATLAB code used for the Markov chain Monte Carlo method fit of absorption data can be found at, and is also available upon request from W.A.T.


  1. 1.

    Green, M. A., Ho-Baillie, A. & Snaith, H. J. The emergence of perovskite solar cells. Nat. Photon. 8, 506–514 (2014).

    CAS  Google Scholar 

  2. 2.

    Lee, M. M. et al. Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338, 643–647 (2012).

    CAS  PubMed  Google Scholar 

  3. 3.

    Stoumpos, C. C. & Kanatzidis, M. G. The renaissance of halide perovskites and their evolution as emerging semiconductors. Acc. Chem. Res. 48, 2791–2802 (2015).

    CAS  PubMed  Google Scholar 

  4. 4.

    Tan, H. et al. Dipolar cations confer defect tolerance in wide-bandgap metal halide perovskites. Nat. Commun. 9, 3100 (2018).

    PubMed  PubMed Central  Google Scholar 

  5. 5.

    Stranks, S. D. et al. Electron-hole diffusion lengths exceeding 1 micrometer in an organometal trihalide perovskite absorber. Science 342, 341–344 (2013).

    CAS  PubMed  Google Scholar 

  6. 6.

    Zhu, X.-Y. & Podzorov, V. Charge carriers in hybrid organic–inorganic lead halide perovskites might be protected as large polarons. J. Phys. Chem. Lett. 6, 4758–4761 (2015).

    CAS  PubMed  Google Scholar 

  7. 7.

    Rong, Y. et al. Challenges for commercializing perovskite solar cells. Science 361, eaat8235 (2018).

    PubMed  Google Scholar 

  8. 8.

    Fairfield, D. J. et al. Structure and chemical stability in perovskite–polymer hybrid photovoltaic materials. J. Mater. Chem. A 7, 1687–1699 (2019).

    CAS  Google Scholar 

  9. 9.

    Chen, A. Z. et al. Origin of vertical orientation in two-dimensional metal halide perovskites and its effect on photovoltaic performance. Nat. Commun. 9, 1336 (2018).

    PubMed  PubMed Central  Google Scholar 

  10. 10.

    Tsai, H. et al. High-efficiency two-dimensional Ruddlesden–Popper perovskite solar cells. Nature 536, 312–316 (2016).

    CAS  PubMed  Google Scholar 

  11. 11.

    Cao, D. H. et al. 2D homologous perovskites as light-absorbing materials for solar cell applications. J. Am. Chem. Soc. 137, 7843–7850 (2015).

    CAS  PubMed  Google Scholar 

  12. 12.

    Smith, I. C. et al. A layered hybrid perovskite solar-cell absorber with enhanced moisture stability. Angew. Chem. Int. Ed. 53, 11232–11235 (2014).

    CAS  Google Scholar 

  13. 13.

    Liao, Y. et al. Highly oriented low-dimensional tin halide perovskites with enhanced stability and photovoltaic performance. J. Am. Chem. Soc. 139, 6693–6699 (2017).

    CAS  PubMed  Google Scholar 

  14. 14.

    Quan, L. N. et al. Ligand-stabilized reduced-dimensionality perovskites. J. Am. Chem. Soc. 138, 2649–2655 (2016).

    CAS  PubMed  Google Scholar 

  15. 15.

    Straus, D. B. & Kagan, C. R. Electrons, excitons, and phonons in two-dimensional hybrid perovskites: connecting structural, optical, and electronic properties. J. Phys. Chem. Lett. 9, 1434–1447 (2018).

    CAS  PubMed  Google Scholar 

  16. 16.

    Mao, L., Stoumpos, C. C. & Kanatzidis, M. G. Two-dimensional hybrid halide perovskites: principles and promises. J. Am. Chem. Soc. 141, 1171–1190 (2019).

    CAS  PubMed  Google Scholar 

  17. 17.

    Hong, X., Ishihara, T. & Nurmikko, A. V. Dielectric confinement effect on excitons in lead tetraiodide-based layered semiconductors. Phys. Rev. B 45, 6961–6964 (1992).

    CAS  Google Scholar 

  18. 18.

    Katan, C., Mercier, N. & Even, J. Quantum and dielectric confinement effects in lower-dimensional hybrid perovskite semiconductors. Chem. Rev. 119, 3140–3192 (2019).

    CAS  PubMed  Google Scholar 

  19. 19.

    Herz, L. M. Charge-carrier dynamics in organic–inorganic metal halide perovskites. Annu. Rev. Phys. Chem. 67, 65–89 (2016).

    CAS  PubMed  Google Scholar 

  20. 20.

    Zhang, S. et al. Synthesis and optical properties of novel organic–inorganic hybrid nanolayer structure semiconductors. Acta Mater. 57, 3301–3309 (2009).

    CAS  Google Scholar 

  21. 21.

    Xing, J. et al. Color-stable highly luminescent sky-blue perovskite light-emitting diodes. Nat. Commun. 9, 3541 (2018).

    PubMed  PubMed Central  Google Scholar 

  22. 22.

    Smith, M. D. et al. Decreasing the electronic confinement in layered perovskites through intercalation. Chem. Sci. 8, 1960–1968 (2017).

    CAS  PubMed  Google Scholar 

  23. 23.

    Evans, H. A. et al. (TTF)Pb2I5: a radical cation-stabilized hybrid lead iodide with synergistic optoelectronic signatures. Chem. Mater. 28, 3607–3611 (2016).

    CAS  Google Scholar 

  24. 24.

    Mitzi, D. B., Chondroudis, K. & Kagan, C. R. Design, structure, and optical properties of organic– inorganic perovskites containing an oligothiophene chromophore. Inorg. Chem. 38, 6246–6256 (1999).

    CAS  PubMed  Google Scholar 

  25. 25.

    Gélvez-Rueda, M. C. et al. Inducing charge separation in solid state 2D hybrid perovskites through the incorporation of organic charge-transfer complexes. J. Phys. Chem. Lett. 11, 824–830 (2020).

    PubMed  PubMed Central  Google Scholar 

  26. 26.

    Van Gompel, W. T. et al. Towards 2D layered hybrid perovskites with enhanced functionality: introducing charge-transfer complexes via self-assembly. Chem. Commun. 55, 2481–2484 (2019).

    CAS  Google Scholar 

  27. 27.

    Nishida, J. et al. Dynamically disordered lattice in a layered Pb-I-SCN perovskite thin film probed by two-dimensional infrared spectroscopy. J. Am. Chem. Soc. 140, 9882–9890 (2018).

    CAS  PubMed  Google Scholar 

  28. 28.

    Wu, X. et al. Trap states in lead iodide perovskites. J. Am. Chem. Soc. 137, 2089–2096 (2015).

    CAS  PubMed  Google Scholar 

  29. 29.

    Straus, D. B. et al. Direct observation of electron–phonon coupling and slow vibrational relaxation in organic–inorganic hybrid perovskites. J. Am. Chem. Soc. 138, 13798–13801 (2016).

    CAS  PubMed  Google Scholar 

  30. 30.

    Thouin, F. et al. Stable biexcitons in two-dimensional metal-halide perovskites with strong dynamic lattice disorder. Phys. Rev. Mater. 2, 034001 (2018).

    CAS  Google Scholar 

  31. 31.

    Smith, I. C. et al. Between the sheets: postsynthetic transformations in hybrid perovskites. Chem. Mater. 29, 1868–1884 (2017).

    CAS  Google Scholar 

  32. 32.

    García-Benito, I. et al. Fashioning fluorous organic spacers for tunable and stable layered hybrid perovskites. Chem. Mater. 30, 8211–8220 (2018).

    Google Scholar 

  33. 33.

    Tan, S. et al. Effect of high dipole moment cation on layered 2D organic–inorganic halide perovskite solar cells. Adv. Ener. Mater. 9, 1803024 (2019).

    Google Scholar 

  34. 34.

    Du, K.-z. et al. Two-dimensional lead(ii) halide-based hybrid perovskites templated by acene alkylamines: crystal structures, optical properties, and piezoelectricity. Inorg. Chem. 56, 9291–9302 (2017).

    CAS  PubMed  Google Scholar 

  35. 35.

    Mitzi, D. B., Medeiros, D. R. & Malenfant, P. R. L. Intercalated organic−inorganic perovskites stabilized by fluoroaryl−aryl interactions. Inorg. Chem. 41, 2134–2145 (2002).

    CAS  PubMed  Google Scholar 

  36. 36.

    Lemmerer, A. & Billing, D. G. Synthesis, characterization and phase transitions of the inorganic–organic layered perovskite-type hybrids [(CnH2n+1NH3)2PbI4], n = 7, 8, 9 and 10. Dalton Trans. 41, 1146–1157 (2012).

    CAS  PubMed  Google Scholar 

  37. 37.

    Billing, D. G. & Lemmerer, A. Synthesis, characterization and phase transitions in the inorganic–organic layered perovskite-type hybrids (CnH2n+1NH3)2PbI4, n = 4, 5 and 6. Acta Crystallogr. B 63, 735–747 (2007).

    CAS  PubMed  Google Scholar 

  38. 38.

    Passarelli, J. V. et al. Enhanced out-of-plane conductivity and photovoltaic performance in n = 1 layered perovskites through organic cation design. J. Am. Chem. Soc. 140, 7313–7323 (2018).

    CAS  PubMed  Google Scholar 

  39. 39.

    Tayi, A. S. et al. Room-temperature ferroelectricity in supramolecular networks of charge-transfer complexes. Nature 488, 485–489 (2012).

    CAS  PubMed  Google Scholar 

  40. 40.

    Blackburn, A. K. et al. Lock-arm supramolecular ordering: a molecular construction set for cocrystallizing organic charge transfer complexes. J. Am. Chem. Soc. 136, 17224–17235 (2014).

    CAS  PubMed  Google Scholar 

  41. 41.

    Tayi, A. S. et al. Supramolecular ferroelectrics. Nat. Chem. 7, 281–294 (2015).

    CAS  PubMed  Google Scholar 

  42. 42.

    Narayanan, A. et al. Ferroelectric polarization and second harmonic generation in supramolecular cocrystals with two axes of charge-transfer. J. Am. Chem. Soc. 139, 9186–9191 (2017).

    CAS  PubMed  Google Scholar 

  43. 43.

    Jacobs, I. E. & Moulé, A. J. Controlling molecular doping in organic semiconductors. Adv. Mater. 29, 1703063 (2017).

    Google Scholar 

  44. 44.

    Salzmann, I. et al. Molecular electrical doping of organic semiconductors: fundamental mechanisms and emerging dopant design rules. Acc. Chem. Res. 49, 370–378 (2016).

    CAS  PubMed  Google Scholar 

  45. 45.

    Lüssem, B., Riede, M. & Leo, K. Doping of organic semiconductors. Phys. Status Solidi A 210, 9–43 (2013).

    Google Scholar 

  46. 46.

    Méndez, H. et al. Charge-transfer crystallites as molecular electrical dopants. Nat. Commun. 6, 8560 (2015).

    PubMed  PubMed Central  Google Scholar 

  47. 47.

    Lüssem, B. R. et al. Doped organic transistors. Chem. Rev. 116, 13714–13751 (2016).

    PubMed  Google Scholar 

  48. 48.

    Pingel, P. & Neher, D. Comprehensive picture of p-type doping of P3HT with the molecular acceptor F4TCNQ. Phys. Rev. B 87, 115209 (2013).

    Google Scholar 

  49. 49.

    Reiser, P. et al. n-Type doping of organic semiconductors: immobilization via covalent anchoring. Chem. Mater. 31, 4213–4221 (2019).

    CAS  Google Scholar 

  50. 50.

    Goud, N. R. & Matzger, A. J. Impact of hydrogen and halogen bonding interactions on the packing and ionicity of charge-transfer cocrystals. Cryst. Growth Des. 17, 328–336 (2017).

    CAS  Google Scholar 

  51. 51.

    Kim, S. H., Lim, W. T. & Heo, N. H. Charge–transfer complex of 2,3-diaminonaphthalene and chloranil: colour development and crystal structure. Dyes Pigments 41, 89–92 (1999).

    CAS  Google Scholar 

  52. 52.

    Goetz, K. P. et al. Charge–transfer complexes: new perspectives on an old class of compounds. J. Mater. Chem. C 2, 3065–3076 (2014).

    CAS  Google Scholar 

  53. 53.

    Dolzhenko, Y. I., Inabe, T. & Maruyama, Y. In situ X-ray observation on the intercalation of weak interaction molecules into perovskite-type layered crystals (C9H19NH3)2PbI4 and (C10H21NH3)2CdCI4. Bull. Chem. Soc. Jpn 59, 563–567 (1986).

    CAS  Google Scholar 

  54. 54.

    Foster, R. Electron donor–acceptor complexes. J. Phys. Chem. 84, 2135–2141 (1980).

    CAS  Google Scholar 

  55. 55.

    Mulliken, R. S. Molecular compounds and their spectra. II. J. Am. Chem. Soc. 74, 811–824 (1952).

    CAS  Google Scholar 

  56. 56.

    Saparov, B. & Mitzi, D. B. Organic–inorganic perovskites: structural versatility for functional materials design. Chem. Rev. 116, 4558–4596 (2016).

    CAS  PubMed  Google Scholar 

  57. 57.

    Blancon, J. C. et al. Scaling law for excitons in 2D perovskite quantum wells. Nat. Commun. 9, 2254 (2018).

    PubMed  PubMed Central  Google Scholar 

  58. 58.

    Neutzner, S. et al. Exciton–polaron spectral structures in two-dimensional hybrid lead-halide perovskites. Phys. Rev. Mater. 2, 064605 (2018).

    CAS  Google Scholar 

  59. 59.

    Ishihara, T., Takahashi, J. & Goto, T. Optical properties due to electronic transitions in two-dimensional semiconductors (CnH2n+1NH3)2PbI4. Phys. Rev. B 42, 11099–11107 (1990).

    CAS  Google Scholar 

  60. 60.

    Even, J. et al. Electronic model for self-assembled hybrid organic/perovskite semiconductors: reverse band edge electronic states ordering and spin-orbit coupling. Phys. Rev. B 86, 205301 (2012).

    Google Scholar 

  61. 61.

    Schlüter, I. C. & Schlüter, M. Electronic structure and optical properties of PbI2. Phys. Rev. B 9, 1652–1663 (1974).

    Google Scholar 

  62. 62.

    Elliott, R. J. Intensity of optical absorption by excitons. Phys. Rev. 108, 1384–1389 (1957).

    CAS  Google Scholar 

  63. 63.

    Tanguy, C. Complex dielectric constant of two-dimensional Wannier excitons. Solid State Commun. 98, 65–68 (1996).

    CAS  Google Scholar 

  64. 64.

    Thygesen, K. S. Calculating excitons, plasmons, and quasiparticles in 2D materials and van der Waals heterostructures. 2D Mater. 4, 022004 (2017).

    Google Scholar 

  65. 65.

    Chernikov, A. et al. Exciton binding energy and nonhydrogenic Rydberg series in monolayer WS2. Phys. Rev. Lett. 113, 076802 (2014).

    PubMed  Google Scholar 

  66. 66.

    Kitazawa, N., Ito, T., Sakasegawa, D. & Watanabe, Y. Excitons in self-organized layered perovskite films prepared by the two-step growth process. Thin Solid Films 500, 133–137 (2006).

    CAS  Google Scholar 

  67. 67.

    Yang, Y. et al. Low surface recombination velocity in solution-grown CH3NH3PbBr3 perovskite single crystal. Nat. Commun. 6, 7961 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  68. 68.

    Tanaka, K. et al. Image charge effect on two-dimensional excitons in an inorganic–organic quantum-well crystal. Phys. Rev. B 71, 045312 (2005).

    Google Scholar 

  69. 69.

    Yaffe, O. et al. Excitons in ultrathin organic–inorganic perovskite crystals. Phys. Rev. B 92, 045414 (2015).

    Google Scholar 

  70. 70.

    Raja, A. et al. Dielectric disorder in two-dimensional materials. Nat. Nanotechnol. 14, 832–837 (2019).

    CAS  PubMed  Google Scholar 

  71. 71.

    Dohner, E. R., Jaffe, A., Bradshaw, L. R. & Karunadasa, H. I. Intrinsic white-light emission from layered hybrid perovskites. J. Am. Chem. Soc. 136, 13154–13157 (2014).

    CAS  PubMed  Google Scholar 

  72. 72.

    Hu, T. et al. Mechanism for broadband white-light emission from two-dimensional (110) hybrid perovskites. J. Phys. Chem. Lett. 7, 2258–2263 (2016).

    CAS  PubMed  Google Scholar 

  73. 73.

    Cortecchia, D. et al. Polaron self-localization in white-light emitting hybrid perovskites. J. Mater. Chem. C 5, 2771–2780 (2017).

    CAS  Google Scholar 

  74. 74.

    Mao, L. et al. White-light emission and structural distortion in new corrugated two-dimensional lead bromide perovskites. J. Am. Chem. Soc. 139, 5210–5215 (2017).

    CAS  PubMed  Google Scholar 

  75. 75.

    Smith, M. D. et al. Structural origins of broadband emission from layered Pb–Br hybrid perovskites. Chem. Sci. 8, 4497–4504 (2017).

    CAS  PubMed  PubMed Central  Google Scholar 

  76. 76.

    Dewar, M. J. S. & Thompson, C. C. Π-molecular complexes—III: a critique for charge-transfer, and stability constants for some TCNE–hydrocarbon complexes. Tetrahedron 22, 97–114 (1966).

    Google Scholar 

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This work was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, under awards numbers DE-FG02-00ER45810 (for synthesis at Northwestern University) and DE-SC0019345 (for spectroscopic studies at the Massachusetts Institute of Technology). Additional support for the X-ray characterization at Northwestern University was provided by the Center for Bio-Inspired Energy Science (CBES), an Energy Frontier Research Center (EFRC) funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award number DE-SC0000989. J.V.P. acknowledges support from Northwestern University through a Ryan Fellowship. C.M.M. was supported by a Postdoctoral Fellowship in Environmental Chemistry from the Camille and Henry Dreyfus Foundation. C.F.P. was funded by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering (award number DE-FG02-07ER46454). NMR and mass spectrometry experiments made use of the Integrated Molecular Structure Education and Research Center at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental Resource (NSF ECCS-1542205), State of Illinois and International Institute for Nanotechnology (IIN). This work also made use of the Electron Probe Instrumentation Center, Keck-II and Scanned Probe Imaging and Development facilities of Northwestern University’s Atomic and Nanoscale Characterization Experimental Center, which has received support from the Soft and Hybrid Nanotechnology Experimental Resource (NSF ECCS-1542205), the Materials Research Science and Engineering Centers programme (DMR-1720139) at the Materials Research Center, the IIN, the Keck Foundation and the State of Illinois, through the IIN. This work made use of the Jerome B. Cohen X-ray Diffraction Facility supported by the Materials Research Science and Engineering Centers programme of the National Science Foundation (DMR-1720139) at the Materials Research Center of Northwestern University (LCP1). GIWAXS experiments were performed at the Advanced Photon Source (Sector 8-ID-E)—a US Department of Energy Office of Science User Facility operated for the Department of Energy Office of Science by Argonne National Laboratory under contract number DE-AC02-06CH11357.

Author information




J.V.P., C.M.M., W.A.T. and S.I.S. conceived of and designed the experiments. J.V.P., J.C.B., H.S. and A.N. performed the experimentation pertaining to structural characterization of TCBQ incorporation. C.M.M. performed the experimentation and analysis pertaining to optical characterization and binding energy determination. S.W.W. performed the Markov chain Monte Carlo analysis. C.F.P. and K.W.W. performed the photoluminescence excitation experiments. C.M.M. and J.V.P. wrote the manuscript with guidance from S.I.S. and W.A.T. All authors discussed the results and analysis and commented on the manuscript.

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Correspondence to William A. Tisdale or Samuel I. Stupp.

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Supplementary information

Supplementary Information

Experimental details regarding the synthesis and characterization of the molecules used in this work; additional characterization data for the perovskite compounds with and without molecular dopant; and extended discussion of incorporation regimes and optical characterization.

Crystallographic Data

1 CIF for compound 3; CCDC reference 1934873.

Crystallographic Data

2 CIF for compound 4; CCDC reference 1934874.

Crystallographic Data

3 CIF for compound 5; CCDC reference 1934872.

Crystallographic Data

4 CIF for compound 6; CCDC reference 1934871.

Crystallographic Data

5 CIF for compound 7; CCDC reference 1934875.

Crystallographic Data

6 CIF for compound 8; CCDC reference 1934876.

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Passarelli, J.V., Mauck, C.M., Winslow, S.W. et al. Tunable exciton binding energy in 2D hybrid layered perovskites through donor–acceptor interactions within the organic layer. Nat. Chem. 12, 672–682 (2020).

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