Resonant four-photon photoemission from SnSe₂(001)

Abstract

High-order nonlinear multiphoton absorption is usually inefficient, but can be enhanced by designing resonant excitations between occupied and unoccupied energy levels. We conducted angle-resolved multi-photon photoemission (mPPE) studies on the SnSe₂(001) surfaces excited by ultrashort laser pulses. By tuning photon energy and light polarization, we demonstrate the presence of a resonant four-photon photoemission (4PPE) process involving the occupied valence band (VB), the unoccupied second conduction band (CB2) and the unoccupied image-potential state (IPs) of SnSe₂. In this 4PPE process, VB electrons of SnSe₂ are resonantly excited into CB2 by adsorbing two photons, followed by the adsorption of another photon to populate the n = 1 IPs before being emitted out to the vacuum by adsorbing one more photon. This results in a double-resonant 4PPE process, which exhibits approximately a 40 times enhancement in photoemission yields compared to cases where one of the resonant pathways, CB2 → IPs, is inhibited by involving a virtual state instead of the IPs in the 4PPE. The double-resonant 4PPE process efficiently excite the bulk VB electrons outside the vacuum, like taking advantage of resonant “ladders” through two real empty electronic states of SnSe₂. Our results highlight the important applications of mPPE in probing the band-structure, particularly the unoccupied states, of recently emerging main group dichalcogenide semiconductors. Furthermore, the discovered resonant mPPE process contributes to the exploration of their promising optoelectronic applications.

Graphical abstract

Keywords

multi-photon photoemission / four-photon photoemission / SnSe₂ / unoccupied states / resonant excitation

References

[1] H. Petek , S. Ogawa . Femtosecond time-resolved two-photon photoemission studies of electron dynamics in metals. Prog. Surf. Sci., 1997, 56(4): 239

[2] T. Fauster , M. Weinelt , U. Höfer . Quasi-elastic scattering of electrons in image-potential states. Prog. Surf. Sci., 2007, 82(4−6): 224

[3] K. Giesen , F. Hage , F. Himpsel , H. Riess , W. Steinmann . Two-photon photoemission via image-potential states. Phys. Rev. Lett., 1985, 55(3): 300

[4] R. Schoenlein , J. G. Fujimoto , G. Eesley , T. Capehart . Femtosecond studies of image-potential dynamics in metals. Phys. Rev. Lett., 1988, 61(22): 2596

[5] C.WaldfriedD.McIlroyJ.ZhangP.DowbenG.KatrichE.W. Plummer, Determination of the surface Debye temperature of Mo(112) using valence band photoemission, Surf. Sci. 363(1‒3), 296 (1996)

[6] F. Bisio , A. Winkelmann , C. Chiang , H. Petek , J. Kirschner . Band structure effects in above threshold photoemission. J. Phys.: Condens. Matter, 2011, 23(48): 485002

[7] A. Winkelmann , W. C. Lin , C. T. Chiang , F. Bisio , H. Petek , J. Kirschner . Resonant coherent three-photon photoemission from Cu(001). Phys. Rev. B, 2009, 80(15): 155128

[8] F. Bisio , M. Nývlt , J. Franta , H. Petek , J. Kirschner . Mechanisms of high-order perturbative photoemission from Cu(001). Phys. Rev. Lett., 2006, 96(8): 087601

[9] M. Reutzel , A. Li , Z. Wang , H. Petek . Coherent multidimensional photoelectron spectroscopy of ultrafast quasiparticle dressing by light. Nat. Commun., 2020, 11(1): 2230

[10] Y. Lin , Y. Li , J. T. Sadowski , W. Jin , J. I. Dadap , M. S. Hybertsen . Excitation and characterization of image potential state electrons on quasi-free-standing graphene. Phys. Rev. B, 2018, 97(16): 165413

[11] A. A. Ünal , C. Tusche , S. Ouazi , S. Wedekind , C. T. Chiang , A. Winkelmann , D. Sander , J. Henk , J. Kirschner . Hybridization between the unoccupied Shockley surface state and bulk electronic states on Cu(111). Phys. Rev. B, 2011, 84(7): 073107

[12] H. Petek , A. Li , X. Li , S. Tan , M. Reutzel . Plasmonic decay into hot electrons in silver. Prog. Surf. Sci., 2023, 98(3): 100707

[13] M. Reutzel , A. Li , H. Petek . Coherent two-dimensional multiphoton photoelectron spectroscopy of metal surfaces. Phys. Rev. X, 2019, 9(1): 011044

[14] S. Ogawa , H. Petek . Two-photon photoemission spectroscopy at clean and oxidized Cu(110) and Cu(100) surfaces. Surf. Sci., 1996, 363(1−3): 313

[15] S. Luan , R. Hippler , H. Schwier , H. Lutz . Electron emission from polycrystalline copper surfaces by multi-photon absorption. Europhys. Lett., 1989, 9(5): 489

[16] W. Fann , R. Storz , J. Bokor . Observation of above-threshold multiphoton photoelectric emission from image-potential surface states. Phys. Rev. B, 1991, 44(19): 10980

[17] S. Irvine , A. Dechant , A. Elezzabi . Generation of 0.4-keV femtosecond electron pulses using impulsively excited surface plasmons. Phys. Rev. Lett., 2004, 93(18): 184801

[18] I.KinoshitaT.AnazawaY.Matsumoto, Surface and image-potential states on Pt(111) probed by two-and three-photon photoemission, Chem. Phys. Lett. 259(3‒4), 445 (1996)

[19] J. Kupersztych , P. Monchicourt , M. Raynaud . Ponderomotive acceleration of photoelectrons in surface-plasmon-assisted multiphoton photoelectric emission. Phys. Rev. Lett., 2001, 86(22): 5180

[20] S. Tan , A. Argondizzo , C. Wang , X. Cui , H. Petek . Ultrafast multiphoton thermionic photoemission from graphite. Phys. Rev. X, 2017, 7(1): 011004

[21] S. Tan , Y. Dai , S. Zhang , L. Liu , J. Zhao , H. Petek . Coherent electron transfer at the Ag/graphite heterojunction interface. Phys. Rev. Lett., 2018, 120(12): 126801

[22] S. Tan , L. Liu , Y. Dai , J. Ren , J. Zhao , H. Petek . Ultrafast plasmon-enhanced hot electron generation at Ag nanocluster/graphite heterojunctions. J. Am. Chem. Soc., 2017, 139(17): 6160

[23] C. A. Formstone , E. T. FitzGerald , D. O’Hare , P. A. Cox , M. Kurmoo , J. W. Hodby , D. Lillicrap , M. Goss-Custard . Observation of superconductivity in the organometallic intercalation compound SnSe₂{Co(η-C₅H₅)₂}_0.33. J. Chem. Soc. Chem. Commun., 1990, 0(6): 501

[24] C. A. Formstone , M. Kurmoo , E. T. FitzGerald , P. A. Cox , D. O’Hare . Single-crystal conductivity study of the tin dichalcogenides SnS_2–xSe_x intercalated with cobaltocene. J. Mater. Chem., 1991, 1(1): 51

[25] D. O’Hare , H. V. Wong , S. Hazell , J. W. Hodby . Relatively isotropic superconductivity at 8.3 K in the Lamellar organometallic intercalate SnSe₂{Co(η-C₅H₅)₂}_0.3. Adv. Mater., 1992, 4(10): 658

[26] Z. Li , Y. Zhao , K. Mu , H. Shan , Y. Guo , J. Wu , Y. Su , Q. Wu , Z. Sun , A. Zhao , X. Cui , C. Wu , Y. Xie . Molecule-confined engineering toward superconductivity and ferromagnetism in two-dimensional superlattice. J. Am. Chem. Soc., 2017, 139(45): 16398

[27] G. R. Bhimanapati , Z. Lin , V. Meunier , Y. Jung , J. Cha , S. Das , D. Xiao , Y. Son , M. S. Strano , V. R. Cooper , L. Liang , S. G. Louie , E. Ringe , W. Zhou , S. S. Kim , R. R. Naik , B. G. Sumpter , H. Terrones , F. Xia , Y. Wang , J. Zhu , D. Akinwande , N. Alem , J. A. Schuller , R. E. Schaak , M. Terrones , J. A. Robinson . Recent advances in two-dimensional materials beyond graphene. ACS Nano, 2015, 9(12): 11509

[28] R. A. Klemm . Pristine and intercalated transition metal dichalcogenide superconductors. Physica C, 2015, 514: 86

[29] X. Zhou , L. Gan , W. Tian , Q. Zhang , S. Jin , H. Li , Y. Bando , D. Golberg , T. Zhai . Ultrathin SnSe₂ flakes grown by chemical vapor deposition for high‐performance photodetectors. Adv. Mater., 2015, 27(48): 8035

[30] A. Giri , G. Park , U. Jeong . Layer-structured anisotropic metal chalcogenides: Recent advances in synthesis, modulation, and applications. Chem. Rev., 2023, 123(7): 3329

[31] E. P. Mukhokosi , G. V. Manohar , T. Nagao , S. B. Krupanidhi , K. K. Nanda . Device architecture for visible and near-infrared photodetectors based on two-dimensional SnSe₂ and MoS₂: A review. Micromachines (Basel), 2020, 11(8): 750

[32] X. Li , L. Li , H. Zhao , S. Ruan , W. Zhang , P. Yan , Z. Sun , H. Liang , K. Tao . SnSe₂ quantum dots: Facile fabrication and application in highly responsive UV-detectors. Nanomaterials (Basel), 2019, 9(9): 1324

[33] E. Mooser , W. B. Pearson . New semiconducting compounds. Phys. Rev., 1956, 101(1): 492

[34] G. Domingo , R. S. Itoga , C. R. Kannewurf . Fundamental optical absorption in SnS₂ and SnSe₂. Phys. Rev., 1966, 143(2): 536

[35] M. Y. Auyang , M. L. Cohen . Electronic structure and optical properties of SnS₂ and SnSe₂. Phys. Rev., 1969, 178(3): 1279

[36] R. Williams , R. Murray , D. Govan , J. Thomas , E. Evans . Band structure and photoemission studies of SnS₂ and SnSe₂. I. Experimental. J. Phys. C Solid State Phys., 1973, 6(24): 3631

[37] R. Cohen , G. Wertheim , A. Rosencwaig , H. Guggenheim . Multiplet splitting of the 4s and 5s electrons of the rare earths. Phys. Rev. B, 1972, 5(3): 1037

[38] G. Domingo , R. Itoga , C. Kannewurf . Fundamental optical absorption in SnS₂ and SnSe₂. Phys. Rev., 1966, 143(2): 536

[39] C. Fong , M. Cohen . Electronic charge densities for two layer semiconductors − SnS₂ and SnSe₂. J. Phys. C Solid State Phys., 1974, 7(1): 107

[40] J. George , K. Joseph . Absorption edge measurements in tin disulphide thin films. J. Phys. D Appl. Phys., 1982, 15(6): 1109

[41] M. Schlüter , M. L. Cohen . Valence-band density of states and chemical bonding for several non-transition-metal layer compounds: SnSe₂, PbI₂, BiI₃, and GaSe. Phys. Rev. B, 1976, 14(2): 424

[42] A. Smith , P. Meek , W. Liang . Raman scattering studies of SnS₂ and SnSe₂. J. Phys. C Solid State Phys., 1977, 10(8): 1321

[43] R. Schlaf , C. Pettenkofer , W. Jaegermann . Band lineup of a SnS₂/SnSe₂/SnS₂ semiconductor quantum well structure prepared by van der Waals epitaxy. J. Appl. Phys., 1999, 85(9): 6550

[44] G. Kresse , J. Furthmüller . Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B, 1996, 54(16): 11169

[45] G. Kresse , J. Furthmüller . Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci., 1996, 6(1): 15

[46] J. P. Perdew , K. Burke , M. Ernzerhof . Generalized gradient approximation made simple. Phys. Rev. Lett., 1996, 77(18): 3865

[47] M. A. Franzman , C. W. Schlenker , M. E. Thompson , R. L. Brutchey . Solution-phase synthesis of SnSe nanocrystals for use in solar cells. J. Am. Chem. Soc., 2010, 132(12): 4060

[48] L. Li , Z. Chen , Y. Hu , X. Wang , T. Zhang , W. Chen , Q. Wang . Single-layer single-crystalline SnSe nanosheets. J. Am. Chem. Soc., 2013, 135(4): 1213

[49] C. Zhang , H. Yin , M. Han , Z. Dai , H. Pang , Y. Zheng , Y. Q. Lan , J. Bao , J. Zhu . Two-dimensional tin selenide nanostructures for flexible all-solid-state supercapacitors. ACS Nano, 2014, 8(4): 3761

[50] X. Zhou , L. Gan , W. Tian , Q. Zhang , S. Jin , H. Li , Y. Bando , D. Golberg , T. Zhai . Ultrathin SnSe₂ flakes grown by chemical vapor deposition for high-performance photodetectors. Adv. Mater., 2015, 27(48): 8035

[51] Y. Zhou , B. Zhang , X. Chen , C. Gu , C. An , Y. Zhou , K. Cai , Y. Yuan , C. Chen , H. Wu , R. Zhang , C. Park , Y. Xiong , X. Zhang , K. Wang , Z. Yang . Pressure‐induced metallization and robust superconductivity in pristine 1T‐SnSe₂. Adv. Electron. Mater., 2018, 4(8): 1800155

[52] A.J. FortyVI. The growth of cadmium iodide crystals (I): Dislocations and spiral growth, Lond. Edinb. Dublin Philos. Mag. J. Sci. 43(336), 72 (1952)

[53] B. E. Brown , D. J. Beerntsen . Layer structure polytypism among niobium and tantalum selenides. Acta Crystallogr., 1965, 18(1): 31

[54] E. Bjerkelund , A. Kjkshus . On the structural properties of the Ta_1+xSe₂ phase. Acta Chem. Scand., 1967, 21: 513

[55] Y.-H. Mao , H. Shan , J.-R. Wu , Z.-J. Li , C.-Z. Wu , X.-F. Zhai , A.-D. Zhao , B. Wang . Observation of pseudogap in SnSe₂ atomic layers grown on graphite. Front. Phys., 2020, 15(4): 43501

[56] Y. M. Zhang , J. Q. Fan , W. L. Wang , D. Zhang , L. Wang , W. Li , K. He , C. L. Song , X. C. Ma , Q. K. Xue . Observation of interface superconductivity in a SnSe₂/epitaxial graphene van der Waals heterostructure. Phys. Rev. B, 2018, 98(22): 220508

[57] E. B. Lochocki , S. Vishwanath , X. Liu , M. Dobrowolska , J. Furdyna , H. G. Xing , K. M. Shen . Electronic structure of SnSe₂ films grown by molecular beam epitaxy. Appl. Phys. Lett., 2019, 114(9): 091602

[58] R. Schlaf , O. Lang , C. Pettenkofer , W. Jaegermann . Band lineup of layered semiconductor heterointerfaces prepared by van der Waals epitaxy: Charge transfer correction term for the electron affinity rule. J. Appl. Phys., 1999, 85(5): 2732

[59] Q. Zhang , M. O. Li , E. B. Lochocki , S. Vishwanath , X. Liu , R. Yan , H. H. Lien , M. Dobrowolska , J. Furdyna , K. M. Shen , G. Cheng , A. R. Hight Walker , D. J. Gundlach , H. G. Xing , N. V. Nguyen . Band offset and electron affinity of MBE-grown SnSe₂. Appl. Phys. Lett., 2018, 112(4): 042108

[60] W. Steinmann . Two‐photon photoemission spectroscopy of electronic states at metal surfaces. Phys. Status Solidi B, 1995, 192(2): 339

[61] J. M. Gonzalez , I. I. Oleynik . Layer-dependent properties of SnS₂ and SnSe₂ two-dimensional materials. Phys. Rev. B, 2016, 94(12): 125443

[62] Y.PeterM.Cardona, Fundamentals of Semiconductors: Physics and Materials Properties, Springer Science & Business Media, 2010

[63] H. Petek , A. Heberle , W. Nessler , H. Nagano , S. Kubota , S. Matsunami , N. Moriya , S. Ogawa . Optical phase control of coherent electron dynamics in metals. Phys. Rev. Lett., 1997, 79(23): 4649

[64] S. Ogawa , H. Nagano , H. Petek , A. Heberle . Optical dephasing in Cu(111) measured by interferometric two-photon time-resolved photoemission. Phys. Rev. Lett., 1997, 78(7): 1339

[65] H. Petek , H. Nagano , S. Ogawa . Hole decoherence of d bands in copper. Phys. Rev. Lett., 1999, 83(4): 832

Declarations

The authors declare that they have no competing interests and there are no conflicts.

Author contributions

C.X.J. and K.H. performed mPPE measurements. H.L.G. and K.H. performed first-principles calculations. X.X.C., Q.Y., C.C.L. assisted with the STM measurements. C.L.W. and N.X. performed ARPES measurements. G.Q.M. and L.M.C. grew the SnSe₂ single crystals. M.F. and L.M.C. initiated the project and experiments. M.F. and L.M.C. analyzed the data and wrote the manuscript with input from all authors.

Data availability

The data that support the findings of this study are available from the corresponding authors upon request.

Electronic supplementary materials

The online version contains supplementary material available at https://doi.org/10.1007/s11467-023-1365-4 and https://journal.hep.com.cn/fop/EN/10.1007/s11467-023-1365-4.

Acknowledgements

We gratefully acknowledge the productive discussions with Shijing Tan, Xuefeng Cui and Hrvoje Petek. This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XD30000000), the National Key R&D Program of China (Grant Nos. 2018YFA0305802 and 2017YFA0303500), and the National Natural Science Foundation of China (Grant No. 11774267). Calculations were performed at the supercomputing center of WHU of China.

RIGHTS & PERMISSIONS

2024 Higher Education Press