Enhanced charge transport in 2D inorganic molecular crystals constructed with charge-delocalized molecules

Abstract

Outstanding charge transport in molecular crystals is of great importance in modern electronics and optoelectronics. The widely adopted strategies to enhance charge transport, such as restraining intermolecular vibration, are mostly limited to organic molecules, which are nearly inoperative in 2D inorganic molecular crystals currently. In this contribution, charge transport in 2D inorganic molecular crystals is improved by integrating charge-delocalized Se₈ rings as building blocks, where the delocalized electrons on Se₈ rings lift the intermolecular orbitals overlap, offering efficient charge transfer channels. Besides, α-Se flakes composed of charge-delocalized Se₈ rings possess small exciton binding energy. Benefitting from these, α-Se flake exhibits excellent photodetection performance with an ultrafast response rate (∼5 µs) and a high detectivity of 1.08 × 10¹¹ Jones. These findings contribute to a deeper understanding of the charge transport of 2D inorganic molecular crystals composed of electron-delocalized inorganic molecules and pave the way for their potential application in optoelectronics.

Keywords

charge transport / delocalized / inorganic molecular crystals / two-dimensional

References

[1] Cao M, Zhang C, Cai Z, et al. Enhanced photoelectrical response of thermodynamically epitaxial organic crystals at the two-dimensional limit. Nat Commun. 2019; 10(1): 756.

[2] Sakai N, Warren R, Zhang F, et al. Adduct-based p-doping of organic semiconductors. Nat Mater. 2021; 20(9): 1248-1254.

[3] Kotadiya NB, Mondal A, Blom PWM, Andrienko D, Wetzelaer GAH. A window to trap-free charge transport in organic semiconducting thin films. Nat Mater. 2019; 18(11): 1182-1186.

[4] Tamura H, Tsukada M, Ishii H, Kobayashi N, Hirose K. Roles of intramolecular and intermolecular electron-phonon coupling on the formation and transport of large polarons in organic semiconductors. Phys Rev B. 2012; 86(3): 035208.

[5] Giri G, Verploegen E, Mannsfeld SC, et al. Tuning charge transport in solution-sheared organic semiconductors using lattice strain. Nature. 2011; 480(7378): 504-508.

[6] Illig S, Eggeman AS, Troisi A, et al. Reducing dynamic disorder in small-molecule organic semiconductors by suppressing large-amplitude thermal motions. Nat Commun. 2016; 7(1): 10736.

[7] Feng X, Peng X, Peng B, et al. Effect of strong intermolecular interaction in 2D inorganic molecular crystals. J Am Chem Soc. 2021; 143(48): 20192-20201.

[8] Feng X, Sun Z, Pei K, et al. 2D inorganic bimolecular crystals with strong in-plane anisotropy for second-order nonlinear optics. Adv Mater. 2020; 32(32): 2003146.

[9] Han W, Huang P, Li L, et al. Two-dimensional inorganic molecular crystals. Nat Commun. 2019; 10(1): 4728.

[10] Liu L, Li P, Zhao Y, et al. Zeolite-like molecules: promising dielectrics for two-dimensional semiconductors. Sci China Mater. 2022; 66(1): 233-240.

[11] Burbank RD. The crystal structure of a-monoclinic selenium. Acta Crystallogr. 1951; 4(2): 140-148.

[12] Wang Q, Yang F, Zhang Y, et al. Space-confined strategy toward large-area two-dimensional single crystals of molecular materials. J Am Chem Soc. 2018; 140(16): 5339-5342.

[13] Yannopoulos SN, Andrikopoulos KS. Raman scattering study on structural and dynamical features of noncrystalline selenium. J Chem Phys. 2004; 121(10): 4747-4758.

[14] Shenasa M, Sainkar S, Lichtman D. XPS study of some selected selenium compounds. J Electron Spectros Relat Phenomena. 1986; 40(4): 329-337.

[15] Grimme S. Do special noncovalent π-π stacking interactions really exist? Angew Chem Int Ed. 2008; 47(18): 3430-3434.

[16] Thakuria R, Nath NK, Saha BK. The nature and applications of π–π interactions: a perspective. Cryst Growth Des. 2019; 19(2): 523-528.

[17] Okamoto T, Kumagai S, Fukuzaki E, et al. Robust, high-performance n-type organic semiconductors. Sci Adv. 2020; 6(18): eaaz0632.

[18] Heyd J, Scuseria GE. Hybrid functionals based on a screened coulomb potential. J Chem Phys. 2003; 118(18): 8207-8215.

[19] Zeng M, Liu J, Zhou L, et al. Bandgap tuning of two-dimensional materials by sphere diameter engineering. Nat Mater. 2020; 19(5): 528-533.

[20] Bafekry A, Faraji M, Fadlallah MM, et al. Prediction of two-dimensional bismuth-based chalcogenides Bi₂X₃(X = S, Se, Te) monolayers with orthorhombic structure: a first-principles study. J Phys D. 2021; 54(39): 395103.

[21] Wu J, Wang F, Li H, et al. Epitaxial growth of 2D ultrathin metastable γ-Bi₂O₃ flakes for high performance ultraviolet photodetection. Small. 2022; 18(3): 2104244.

[22] Chuang CHM, Brown PR, Bulović V, Bawendi MG. Improved performance and stability in quantum dot solar cells through band alignment engineering. Nat Mater. 2014; 13(8): 796-801.

[23] Qi F, Lin FR, Jen AKY. Selenium: a unique member in the chalcogen family for conjugated materials used in perovskite and organic solar cells. Sol RRL. 2022; 6(7): 2200156.

[24] Lin Z, Wang Z, Chen W, Lin L. Influence of the ring-ring interaction in Se₈-ring clusters on their absorption. J Mater Sci Lett. 1997; 16(9): 732-734.

[25] McGarry KA, Xie W, Sutton C, et al. Rubrene-based single-crystal organic semiconductors: synthesis, electronic structure, and sharge-transpor. properties. Chem Mater. 2013; 25(11): 2254-2263.

[26] Wang C, Zhang X, Dong H, Chen X, Hu W. Challenges and emerging opportunities in high-mobility and low-energy-consumption organic field-effect transistors. Adv Energy Mater. 2020; 10(29): 2000955.

[27] Yuan L, Wang L, Garrigues AR, et al. Transition from direct to inverted charge transport Marcus regions in molecular junctions via molecular orbital gating. Nat Nanotechnol. 2018; 13(4): 322-329.

[28] Yang K, Zhang T, Wei B, et al. Ultrathin high-κ antimony oxide single crystals. Nat Commun. 2020; 11(1): 2502.

[29] Canavaa B, Vignerona J, Etcheberrya A, Guillemolesb JF, Lincotb D. High resolution XPS studies of Se chemistry of a Cu(In, Ga)Se₂ surface. Appl Surf Sci. 2002; 202(1-2): 8-14.

[30] Zhu L, Wei Z, Yi Y. Exciton binding energies in organic photovoltaic materials: a theoretical perspective. J Phys Chem C. 2021; 126(1): 14-21.

[31] Zhu L, Zhang J, Guo Y, Yang C, Yi Y, Wei Z. Small exciton binding energies enabling direct charge photogeneration towards low-driving-force organic solar cells. Angew Chem Int Ed. 2021; 133(28): 15476-15481.

[32] Zhu L, Tu Z, Yi Y, Wei Z. Achieving small exciton binding energies in small molecule acceptors for organic solar cells: effect of molecular packing. J Phys Chem Lett. 2019; 10(17): 4888-4894.

[33] Castet F, Aurel P, Fritsch A, et al. Electronic polarization effects on charge carriers in anthracene: a valence bond study. Phys Rev B. 2008; 77(11): 115210.

[34] Wang F, Li L, Huang W, et al. Submillimeter 2D Bi₂Se₃ flakes toward high-performance infrared photodetection at optical communication wavelength. Adv Funct Mater. 2018; 28(33): 1802707.

[35] Qin J, Qiu G, Jian J, et al. Controlled growth of a large-size 2D selenium nanosheet and its electronic and optoelectronic applications. ACS Nano. 2017; 11(10): 10222-10229.

[36] Han J, Wang F, Han S, et al. Recent progress in 2D inorganic/organic charge transfer heterojunction photodetector. Adv Funct Mater. 2022; 32(34): 2205150.

[37] Liu X, Luo X, Nan H, et al. Epitaxial ultrathin organic crystals on graphene for high-efficiency phototransistors. Adv Mater. 2016; 28(26): 5200-5205.

[38] Sun M, Yang P, Xie D, et al. Self-powered MoS₂-PDPP₃T heterotransistor-based broadband photodetectors. Adv Electron. 2018; 5(2): 1800580.

[39] Han J, Wang J, Yang M, et al. Graphene/organic semiconductor heterojunction phototransistors with broadband and Bi-directional photoresponse. Adv Mater. 2018; 30(49): 1804020.

[40] Alvarado SF, Seidler PF. Direct determination of the exciton binding energy of conjugated polymers. Phys Rev Lett. 1998; 81(5): 1082-1085.

[41] Yang D, Ma D. Development of organic semiconductor photodetectors: from mechanism to applications. Adv Opt Mater. 2019; 7(1): 1800522.

[42] Marple M, Badger J, Hung I, Gan Z, Kovnir K, Sen S. Structure of amorphous selenium by 2D ⁷⁷Se NMR spectroscopy: an end to the dilemma of chain versus ring. Angew Chem Int Ed. 2017; 56(33): 9777-9781.

[43] Cherin P, Unger P. Refinement of the crystal structure of α-monoclinic Se. Acta Crystallogr. 1972; 28(1): 313-317.

[44] Zuo N, Nie A, Hu C, et al. Synergistic additive-assisted growth of 2D ternary In₂SnS₄ with giant gate-tunable polarization-sensitive photoresponse. Small. 2021; 17(18): 2008078.

[45] Li G, Zhang H, Li Y, et al. Ultra-broadband, fast, and polarization-sensitiv. photoresponse of low-symmetry 2D NdSb₂. Nano Res. 2022; 15(6): 5469-5475.

[46] Liu C, Hwang YJ, Jeong HE, Yang P. Light-induced charge transport within a single asymmetric nanowire. Nano Lett. 2011; 11(9): 3755-3758.

[47] Yoo H, Bae C, Yang Y, et al. Spatial charge separation in asymmetric structure of Au nanoparticle on TiO₂ nanotube by light-induced surface potential imaging. Nano Lett. 2014; 14(8): 4413-4417.

[48] Yiming N, Wang Y, Chen J, et al. Patterning the consecutive Pd₃ to Pd₁ on Pd₂Ga surface via temperature-promoted reactive metal-support interaction. Sci Adv. 2022; 8(49): eabq5751.

[49] Ni B, Mychinko M, Gomez-Grana S. et al. Chiral seeded growth of gold nanorods into fourfold twisted nanoparticles with plasmonic optical activity. Adv Mater. 2023; 35(1): 2208299.

[50] Wu Z, Zhou Y, Hai C, et al. Analysis of the growth mechanism of hierarchical structure Ni_0.8Co_0.1Mn_0.1(OH)₂ agglomerates as precursors of LiNi_0.8Co_0.1Mn_0.1O₂ in the presence of aqueous ammonia. Appl Surf Sci. 2023; 619: 156379.

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