Photoinduced electronic band dynamics and defect-mediated surface potential evolution in PdSe2
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Abstract
Abstract We use time- and angle-resolved photoemission spectroscopy (TR-ARPES) combined with density functional theory to investigate ultrafast carrier dynamics in low-symmetry layered semiconducting PdSe 2 . The indirect bandgap is determined to be 0.55 eV. Following photoexcitation above this gap, we resolve a valence band shift and broadening, both lasting less than a picosecond, consistent with bandgap renormalization and carrier scattering, indicative of strong many-body interactions. Subsequently, hot carriers populate the conduction band minimum and are captured by defect states. A surface photovoltage (SPV) of ~67 meV emerges, persisting for over 50 ps, driven by defect-assisted charge separation. The formation of native vacancies, promoted by the low-symmetry lattice, likely gives rise to the mid-gap states responsible for this long-lived SPV response. Detailed analysis of TR-ARPES spectra disentangles the contributions of bandgap renormalization, carrier scattering, defect states, and SPV. These findings establish PdSe 2 as a prototypical layered quantum material exhibiting exotic photoresponses on ultrafast timescales.
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OpenAlex topics: Chalcogenide Semiconductor Thin Films · 2D Materials and Applications · Electronic and Structural Properties of Oxides
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References (70)
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1. Manzeli, S., Ovchinnikov, D., Pasquier, D., Yazyev, O. V. & Kis, A. 2D transition metal dichalcogenides. Nat. Rev. Mater. 2, 1–15 (2017).10.1038/natrevmats.2017.33 ↗
2. Kumar, V. P., Raut, P., Panda, D. K. & Rashed, A. N. Z. Exploring next-generation tmdc materials: A comprehensive review of their classifications, properties, and applications. Silicon 1–23 (2025).10.1007/s12633-025-03274-y ↗
3. Setayeshmehr, K., Hashemi, M. & Ansari, N. Photoconversion efficiency in atomically thin tmdc-based heterostructures. Opt. Express 29, 32910–32921 (2021).10.1364/OE.438386 ↗
4. Schneider, C., Glazov, M. M., Korn, T., Höfling, S. & Urbaszek, B. Two-dimensional semiconductors in the regime of strong light-matter coupling. Nat. Commun. 9, 2695 (2018).10.1038/s41467-018-04866-6 ↗
5. Mak, K. F. & Shan, J. Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides. Nat. Photonics 10, 216–226 (2016).10.1038/nphoton.2015.282 ↗
6. Samy, O., Zeng, S., Birowosuto, M. D. & El Moutaouakil, A. A review on MoS2 properties, synthesis, sensing applications and challenges. Crystals 11, 355 (2021).10.3390/cryst11040355 ↗
7. Oyedele, A. D. et al. PdSe2: pentagonal two-dimensional layers with high air stability for electronics. J. Am. Chem. Soc. 139, 14090–14097 (2017).10.1021/jacs.7b04865 ↗
8. Xia, F., Wang, H. & Jia, Y. Rediscovering black phosphorus as an anisotropic layered material for optoelectronics and electronics. Nat. Commun. 5, 4458 (2014).10.1038/ncomms5458 ↗
9. Morita, A. Semiconducting black phosphorus. Appl. Phys. A 39, 227–242 (1986).10.1007/BF00617267 ↗
10. Sierra, J. F. et al. Room-temperature anisotropic in-plane spin dynamics in graphene induced by PdSe2 proximity. Nature Materials 1–7 (2025).10.1038/s41563-024-02109-2 ↗
11. Long, M. et al. Palladium diselenide long-wavelength infrared photodetector with high sensitivity and stability. ACS Nano 13, 2511–2519 (2019).
12. Pi, L. et al. Recent progress on 2D noble-transition-metal dichalcogenides. Adv. Funct. Mater. 29, 1904932 (2019).10.1002/adfm.201904932 ↗
13. Hassan, A., Guo, Y. & Wang, Q. Performance of the pentagonal PdSe2 sheet as a channel material in contact with metal surfaces and graphene. ACS Appl. Electron. Mater. 2, 2535–2542 (2020).10.1021/acsaelm.0c00438 ↗
14. Wu, D. et al. Highly polarization-sensitive, broadband, self-powered photodetector based on graphene PdSe2 germanium heterojunction. ACS Nano 13, 9907–9917 (2019).10.1021/acsnano.9b03994 ↗
15. Lan, Y.-S., Chen, X.-R., Hu, C.-E., Cheng, Y. & Chen, Q.-F. Penta-PdX2 (X=S, Se, Te) monolayers: promising anisotropic thermoelectric materials. J. Mater. Chem. A 7, 11134–11142 (2019).10.1039/C9TA02138H ↗
16. Zeng, L.-H. et al. Controlled synthesis of 2D palladium diselenide for sensitive photodetector applications. Adv. Funct. Mater. 29, 1806878 (2019).10.1002/adfm.201806878 ↗
17. Deng, S., Li, L. & Zhang, Y. Strain modulated electronic, mechanical, and optical properties of the monolayer PdS2, PdSe2, and PtSe2 for tunable devices. ACS Appl. Nano Mater. 1, 1932–1939 (2018).10.1021/acsanm.8b00363 ↗
18. Gu, Y. et al. Two-dimensional palladium diselenide with strong in-plane optical anisotropy and high mobility grown by chemical vapor deposition. Adv. Mater. 32, 1906238 (2020).10.1002/adma.201906238 ↗
19. Liang, Q. et al. High-performance, room temperature, ultra-broadband photodetectors based on air-stable PdSe2. Adv. Mater. 31, 1807609 (2019).10.1002/adma.201807609 ↗
20. Liu, M. et al. Uncooled near-to long-wave-infrared polarization-sensitive photodetectors based on MoSe2/PdSe2 van der Waals heterostructures. Nat. Commun. 16, 2774 (2025).10.1038/s41467-025-58155-0 ↗
21. Luo, W. et al. Anisotropic phonon response of few-layer PdSe2 under uniaxial strain. Adv. Funct. Mater. 30, 2003215 (2020).10.1002/adfm.202003215 ↗
22. Abdul-Aziz, O. et al. Resonance-induced anomalies in temperature-dependent Raman scattering of PdSe2. J. Mater. Chem. C. 12, 11402–11411 (2024).10.1039/D4TC02012J ↗
23. Liang, Q. et al. Performance improvement by ozone treatment of 2D PdSe2. ACS nano 14, 5668–5677 (2020).10.1021/acsnano.0c00180 ↗
24. Yu, J. et al. Direct observation of the linear dichroism transition in two-dimensional palladium diselenide. Nano Lett. 20, 1172–1182 (2020).10.1021/acs.nanolett.9b04598 ↗
25. Zhu, R. et al. Observation of anisotropic magnetoresistance in layered nonmagnetic semiconducting PdSe2. ACS Appl. Mater. Interfaces 13, 37527–37534 (2021).10.1021/acsami.1c10500 ↗
26. Soulard, C. et al. Experimental and theoretical investigation on the relative stability of the PdS2-and pyrite-type structures of PdSe2. Inorg. Chem. 43, 1943–1949 (2004).10.1021/ic0352396 ↗
27. ElGhazali, M. A. et al. Pressure-induced superconductivity up to 13.1 k in the pyrite phase of palladium diselenide PdSe2. Phys. Rev. B 96, 060509 (2017).10.1103/PhysRevB.96.060509 ↗
28. Nishiyama, W. et al. Is the bandgap of bulk PdSe2 located truly in the far-infrared region? determination by fourier-transform photocurrent spectroscopy. Adv. Photonics Res. 3, 2200231 (2022).10.1002/adpr.202200231 ↗
29. Nishiyama, W. et al. Quantitative determination of contradictory bandgap values of bulk PdSe2 from electrical transport properties. Adv. Funct. Mater. 32, 2108061 (2022).10.1002/adfm.202108061 ↗
30. Sun, J., Shi, H., Siegrist, T. & Singh, D. J. Electronic, transport, and optical properties of bulk and mono-layer PdSe2. Appl. Phys. Lett.107 (2015).10.1063/1.4933302 ↗
31. Wei, M. et al. Layer-dependent optical and dielectric properties of centimeter-scale PdSe2 films grown by chemical vapor deposition. npj 2D Mater. Appl. 6, 1 (2022).10.1038/s41699-021-00282-5 ↗
32. Zhao, X. et al. Electronic and optical properties of PdSe2 from monolayer to trilayer. Superlatt. Microstruct. 142, 106514 (2020).10.1016/j.spmi.2020.106514 ↗
33. Kuklin, A. V. & Ågren, H. Quasiparticle electronic structure and optical spectra of single-layer and bilayer PdSe2: Proximity and defect-induced band gap renormalization. Phys. Rev. B 99, 245114 (2019).10.1103/PhysRevB.99.245114 ↗
34. Li, Z. et al. Phonon-assisted electronic states modulation of few-layer PdSe2 at terahertz frequencies. npj 2D Mater. Appl. 5, 87 (2021).10.1038/s41699-021-00268-3 ↗
35. Cattelan, M., Sayers, C., Wolverson, D. & Carpene, E. Site-specific symmetry sensitivity of angle-resolved photoemission spectroscopy in layered palladium diselenide. 2D Mater. 8, 045036 (2021).10.1088/2053-1583/ac255a ↗
36. Gu, C. et al. Low-lying electronic states with a giant linear dichroic ratio observed in PdSe2. Phys. Rev. B 106, L121110 (2022).10.1103/PhysRevB.106.L121110 ↗
37. Chung, Y. et al. Dark states of electrons in a quantum system with two pairs of sublattices. Nat. Phys. 20, 1582–1588 (2024).10.1038/s41567-024-02586-x ↗
38. Ryu, J. H. et al. Direct observation of orbital driven strong interlayer coupling in puckered two-dimensional PdSe2. Small 18, 2106053 (2022).10.1002/smll.202106053 ↗
39. Kim, J. et al. Observation of tunable band gap and anisotropic Dirac semimetal state in black phosphorus. Science 349, 723–726 (2015).10.1126/science.aaa6486 ↗
40. Shan, S. et al. Matrix element effect in layered PdSe2. J, Phys, Chem, C (2025).10.1021/acs.jpcc.5c00015 ↗
41. Boschini, F., Zonno, M. & Damascelli, A. Time-resolved ARPES studies of quantum materials. Rev. Mod. Phys. 96, 015003 (2024).10.1103/RevModPhys.96.015003 ↗
42. Aeschlimann, M. et al. Time-resolved photoelectron spectroscopy at surfaces. Surf. Sci. 753, 122631 (2025).10.1016/j.susc.2024.122631 ↗
43. Hedayat, H. et al. Ultrafast evolution of bulk, surface and surface resonance states in photoexcited Bi2Te3. Sci. Rep. 11, 4924 (2021).10.1038/s41598-021-83848-z ↗
44. Hedayat, H. et al. Non-equilibrium band broadening, gap renormalization and band inversion in black phosphorus. 2D Mater. 8, 025020 (2021).10.1088/2053-1583/abd89a ↗
45. Kremer, G. et al. Ultrafast dynamics of the surface photovoltage in potassium-doped black phosphorus. Phys. Rev. B 104, 035125 (2021).10.1103/PhysRevB.104.035125 ↗
46. Chen, Z. et al. Band gap renormalization, carrier multiplication, and Stark broadening in photoexcited black phosphorus. Nano Lett. 19, 488–493 (2018).10.1021/acs.nanolett.8b04344 ↗
47. Roth, S. et al. Photocarrier-induced band-gap renormalization and ultrafast charge dynamics in black phosphorus. 2D Mater. 6, 031001 (2019).10.1088/2053-1583/ab1216 ↗
48. Gierster, L., Vempati, S. & Stähler, J. Ultrafast generation and decay of a surface metal. Nat. Commun. 12, 978 (2021).10.1038/s41467-021-21203-6 ↗
49. Weinelt, M. et al. Electronic structure and electron dynamics at Si (100). Appl. Phys. A 80, 995–1003 (2005).10.1007/s00339-004-3127-7 ↗
50. Weinelt, M., Kutschera, M., Fauster, T. & Rohlfing, M. Dynamics of exciton formation at the Si (100) c (4×2) surface. Phys. Rev. Lett. 92, 126801 (2004).10.1103/PhysRevLett.92.126801 ↗
51. Ciocys, S., Morimoto, T., Moore, J. & Lanzara, A. Tracking surface photovoltage dipole geometry in Bi2Se3 with time-resolved photoemission. J. Stat. Mech.: Theory Exp. 2019, 104008 (2019).10.1088/1742-5468/ab458a ↗
52. Yang, S.-L., Sobota, J. A., Kirchmann, P. S. & Shen, Z.-X. Electron propagation from a photo-excited surface: implications for time-resolved photoemission. Appl. Phys. A 116, 85–90 (2014).10.1007/s00339-013-8154-9 ↗
53. Ulstrup, S. et al. Ramifications of optical pumping on the interpretation of time-resolved photoemission experiments on graphene. J. Electron Spectrosc. Relat. Phenom. 200, 340–346 (2015).10.1016/j.elspec.2015.04.010 ↗
54. Ciocys, S. et al. Manipulating long-lived topological surface photovoltage in bulk-insulating topological insulators =Bi2Se3 and Bi2Te3. npj Quantum Mater. 5, 1–7 (2020).10.1038/s41535-020-0218-4 ↗
55. Kuklin, A. V., Begunovich, L. V., Gao, L., Zhang, H. & Ågren, H. Point and complex defects in monolayer PdSe2: Evolution of electronic structure and emergence of magnetism. Phys. Rev. B 104, 134109 (2021).10.1103/PhysRevB.104.134109 ↗
56. Jena, T. et al. Evidence for intrinsic defects and nanopores as hotspots in 2D PdSe2 dendrites for plasmon-free sers substrate with a high enhancement factor. npj 2D Mater. Appl. 7, 8 (2023).10.1038/s41699-023-00367-3 ↗
57. Nguyen, G. D. et al. 3d imaging and manipulation of subsurface selenium vacancies in PdSe2. Phys. Rev. Lett. 121, 086101 (2018).10.1103/PhysRevLett.121.086101 ↗
58. Grønvold, F. & Røst, E. The crystal structure of PdSe2 and PdS2. Acta Crystallogr. 10, 329–331 (1957).10.1107/S0365110X57000948 ↗
59. Zhang, Y. et al. Quantum octets in high mobility pentagonal two-dimensional PdSe2. Nat. Commun. 15, 761 (2024).10.1038/s41467-024-44972-2 ↗
60. Gao, L., Hu, Z., Lu, J., Liu, H. & Ni, Z. Defect-related dynamics of photoexcited carriers in 2D transition metal dichalcogenides. Phys. Chem. Chem. Phys. 23, 8222–8235 (2021).10.1039/D1CP00006C ↗
61. HQ Graphene. Hq graphene official website. https://www.hqgraphene.com/ (2025). Accessed: 2025-03-28.
62. Peli, S. et al. Time-resolved vuv ARPES at 10.8 ev photon energy and MHz repetition rate. J. Electron Spectrosc. Relat. Phenom. 243, 146978 (2020).10.1016/j.elspec.2020.146978 ↗
63. Giannozzi, P. et al. Quantum espresso: a modular and open-source software project for quantumsimulations of materials. J. Phys. Condens. matter 21, 395502 (2009).10.1088/0953-8984/21/39/395502 ↗
64. Giannozzi, P. et al. Advanced capabilities for materials modelling with Quantum ESPRESSO. J. Phys.: Condens. matter 29, 465901 (2017).
65. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865 (1996).10.1103/PhysRevLett.77.3865 ↗
66. Monkhorst, H. J. & Pack, J. D. Special points for brillouin-zone integrations. Phys. Rev. B 13, 5188 (1976).10.1103/PhysRevB.13.5188 ↗
67. Bartók, A. P. & Yates, J. R. Regularized scan functional. The Journal of chemical physics150 (2019).10.1063/1.5094646 ↗
68. Sabatini, R., Gorni, T. & De Gironcoli, S. Nonlocal van der waals density functional made simple and efficient. Phys. Rev. B-Condens. Matter Mater. Phys. 87, 041108 (2013).10.1103/PhysRevB.87.041108 ↗
69. Heyd, J., Scuseria, G. E. & Ernzerhof, M. Hybrid functionals based on a screened coulomb potential. J. Chem. Phys. 118, 8207–8215 (2003).10.1063/1.1564060 ↗
70. Mostofi, A. A. et al. An updated version of wannier90: A tool for obtaining maximally-localised wannier functions. Computer Phys. Commun. 185, 2309–2310 (2014).10.1016/j.cpc.2014.05.003 ↗