Skip to main content
SpringerLink
Log in

Density of states characterization of TiO2 films deposited by pulsed laser deposition for heterojunction solar cells

  • Research Article
  • Published:
Nano Research Aims and scope Submit manuscript

Abstract

The application of titanium dioxide (TiO2) in the photovoltaic (PV) field is gaining traction as this material can be deployed in doping-free heterojunction solar cells with the role of electron selective contact. For modeling-based optimization of such contact, knowledge of the titanium oxide defect density of states (DOS) is crucial. In this paper, we report a method to extract the defect density through nondestructive optical measures, including the contribution given by small polaron optical transitions. The presence of both related to oxygen-vacancy defects and polarons is supported by the results of optical characterizations and the evaluation of previous observations resulting in a defect band fixed at 1 eV below the conduction band edge of the oxide. Solar cells employing pulsed laser deposited-TiO2 electron selective contacts were fabricated and characterized. The J-V curve of these cells showed, however, an S-shape, then a detailed analysis of the reasons for such behavior was carried out. We use a model involving the series of a standard cell equivalent circuit with a Schottky junction in order to explain these atypical performances. A good matching between the experimental measurements and the adopted theoretical model was obtained. The extracted parameters are listed and analyzed to shed light on the reasons behind the low-performance cells.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Philipps, S.; Warmuth, W. Photovoltaics Report; Fraunhofer ISE: Freiburg, 2021. https://www.ise.fraunhofer.de/content/dam/ise/de/documents/publications/studies/Photovoltaics-Report.pdf (accessed Oct 1, 2021).

    Google Scholar 

  2. Green, M.; Dunlop, E.; Hohl-Ebinger, J.; Yoshita, M.; Kopidakis, N.; Hao, X. J. Solar cell efficiency tables (Version 57). Prog. Photovoltaics Res. Appl. 2021, 29, 3–15.

    Article  Google Scholar 

  3. Yoshikawa, K.; Kawasaki, H.; Yoshida, W.; Irie, T.; Konishi, K.; Nakano, K.; Uto, T.; Adachi, D.; Kanematsu, M.; Uzu, H. et al. Silicon heterojunction solar cell with interdigitated back contacts for a photoconversion efficiency over 26%. Nat. Energy 2017, 2, 17032.

    Article  CAS  Google Scholar 

  4. Enel Green Power. New Efficiency Record for the Innovative Solar Cells Produced by 3SUN Based on Heterojunction Technology [Online]. https://www.enelgreenpower.com/media/news/2020/02/3sun-solar-cell-bifacials-efficiency-record (accessed Mar 11, 2021).

  5. McEvoy, A.; Markvart, T.; Castañer, L. Practical Handbook of Photovoltaics; Elsevier: Amsterdam, 2012.

    Google Scholar 

  6. Holman, Z. C.; Descoeudres, A.; Barraud, L.; Fernandez, F. Z.; Seif, J. P.; De Wolf, S.; Ballif, C. Current losses at the front of silicon heterojunction solar cells. IEEE J. Photovoltaics 2012, 2, 7–15.

    Article  Google Scholar 

  7. Bullock, J.; Hettick, M.; Geissbühler, J.; Ong, A. J.; Allen, T.; Sutter-Fella, C. M.; Chen, T.; Ota, H.; Schaler, E. W.; De Wolf, S. et al. Efficient silicon solar cells with dopant-free asymmetric heterocontacts. Nat. Energy 2016, 1, 15031.

    Article  CAS  Google Scholar 

  8. Melskens, J.; Van De Loo, B. W. H.; Macco, B.; Black, L. E.; Smit, S.; Kessels, W. M. M. Passivating contacts for crystalline silicon solar cells: From concepts and materials to prospects. IEEE J. Photovoltaics 2018, 8, 373–388.

    Article  Google Scholar 

  9. Cho, J.; Melskens, J.; Debucquoy, M.; Payo, M. R.; Jambaldinni, S.; Bearda, T.; Gordon, I.; Szlufcik, J.; Kessels, W. M. M.; Poortmans, J. Passivating electron-selective contacts for silicon solar cells based on an a-Si:H/TiOx stack and a low work function metal. Prog. Photovoltaics Res. Appl. 2018, 26, 835–845.

    Article  CAS  Google Scholar 

  10. Ding, J. N.; Zhou, Y. R.; Dong, G. Q.; Liu, M.; Yu, D. H.; Liu, F. Z. Solution-processed ZnO as the efficient passivation and electron selective layer of silicon solar cells. Prog. Photovoltaics Res. Appl. 2018, 26, 974–980.

    Article  CAS  Google Scholar 

  11. Yang, X. B.; Aydin, E.; Xu, H.; Kang, J. X.; Hedhili, M.; Liu, W. Z.; Wan, Y. M.; Peng, J.; Samundsett, C.; Cuevas, A. et al. Tantalum nitride electron-selective contact for crystalline silicon solar cells. Adv. Energy Mater. 2018, 8, 1800608.

    Article  Google Scholar 

  12. Horynová, E.; Romanyuk, O.; Horák, L.; Remeš, Z.; Conrad, B.; Amalathas, A. P.; Landová, L.; Houdková, J.; Jiříček, P.; Finsterle, T. et al. Optical characterization of low temperature amorphous MoOx, WOx, and VOx prepared by pulsed laser deposition. Thin Solid Films 2020, 693, 137690.

    Article  Google Scholar 

  13. Scire, D.; Bonadonna, M.; Zhao, Y. F.; Procel, P.; Isabella, O.; Zeman, M.; MacAluso, R.; Mosca, M.; Crupi, I. Analysis of transition metal oxides based heterojunction solar cells with S-shaped J- V curves. In Proceedings of the 12th AEIT International Annual Conference, Catania, 2020, pp 1–6.

  14. Messmer, C.; Bivour, M.; Schön, J.; Hermle, M. Requirements for efficient hole extraction in transition metal oxide-based silicon heterojunction solar cells. J. Appl. Phys. 2018, 124, 085702.

    Article  Google Scholar 

  15. Gesheva, K.; Ivanova, T.; Bodurov, G.; Szilágyi, I. M.; Justh, N.; Kéri, O.; Boyadjiev, S.; Nagy, D.; Aleksandrova, M. Technologies for deposition of transition metal oxide thin films: Application as functional layers in “smart windows” and photocatalytic systems. J. Phys. Conf Ser. 2016, 682, 012011.

    Article  Google Scholar 

  16. Mews, M.; Lemaire, A.; Korte, L. Sputtered tungsten oxide as hole contact for silicon heterojunction solar cells. IEEE J. Photovoltaics 2017, 7, 1209–1215.

    Article  Google Scholar 

  17. Mallem, K.; Kim, Y. J.; Hussain, S. Q.; Dutta, S.; Le, A. H. T.; Ju, M.; Park, J.; Cho, Y. H.; Kim, Y.; Cho, E. C. et al. Molybdenum oxide: A superior hole extraction layer for replacing p-type hydrogenated amorphous silicon with high efficiency heterojunction Si solar cells. Mater. Res. Bull. 2019, 110, 90–96.

    Article  CAS  Google Scholar 

  18. Yu, C.; Xu, S. Z.; Yao, J. X.; Han, S. W. Recent advances in and new perspectives on crystalline silicon solar cells with carrier-selective passivation contacts. Crystals 2018, 8, 430.

    Article  Google Scholar 

  19. Dréon, J.; Jeangros, Q.; Cattin, J.; Haschke, J.; Antognini, L.; Ballif, C.; Boccard, M. 23.5%-efficient silicon heterojunction silicon solar cell using molybdenum oxide as hole-selective contact. Nano Energy 2020, 70, 104495.

    Article  Google Scholar 

  20. Perego, M.; Seguini, G.; Scarel, G.; Fanciulli, M.; Wallrapp, F. Energy band alignment at TiO2/Si interface with various interlayers. J. Appl. Phys. 2008, 103, 043509.

    Article  Google Scholar 

  21. Matsui, T.; Bivour, M.; Ndione, P. F.; Bonilla, R. S.; Hermle, M. Origin of the tunable carrier selectivity of atomic-layer-deposited TiOx nanolayers in crystalline silicon solar cells. Sol. Energy Mater. Sol. Cells 2020, 209, 110461.

    Article  CAS  Google Scholar 

  22. Yang, J. F.; Li, L.; Li, W. S.; Mao, L. F. Formation mechanism of conduction path in titanium dioxide with Ti-interstitials-doped: Carparrinello molecular dynamics. AIP Conf. Proc. 2017, 1794, 020024.

    Article  Google Scholar 

  23. Yang, X. B.; Bi, Q. Y.; Ali, H.; Davis, K.; Schoenfeld, W. V.; Weber, K. High-performance TiO2-based electron-selective contacts for crystalline silicon solar cells. Adv. Mater. 2016, 28, 5891–5897.

    Article  CAS  Google Scholar 

  24. Nagamatsu, K. A.; Avasthi, S.; Sahasrabudhe, G.; Man, G.; Jhaveri, J.; Berg, A. H.; Schwartz, J.; Kahn, A.; Wagner, S.; Sturm, J. C. Titanium dioxide/silicon hole-blocking selective contact to enable double-heterojunction crystalline silicon-based solar cell. Appl. Phys. Lett. 2015, 106, 123906.

    Article  Google Scholar 

  25. Yang, X. B.; Weber, K.; Hameiri, Z.; De Wolf, S. Industrially feasible, dopant-free, carrier-selective contacts for high-efficiency silicon solar cells. Prog. Photovoltaics Res. Appl. 2017, 25, 896–904.

    Article  CAS  Google Scholar 

  26. Allen, T. G.; Bullock, J.; Jeangros, Q.; Samundsett, C.; Wan, Y.; Cui, J.; Hessler-Wyser, A.; De Wolf, S.; Javey, A.; Cuevas, A. A low resistance calcium/reduced titania passivated contact for high efficiency crystalline silicon solar cells. Adv. Energy Mater. 2017, 7, 1602606.

    Article  Google Scholar 

  27. Huh, D.; Oh, K.; Kim, M.; Choi, H. J.; Kim, D. S.; Lee, H. Selectively patterned TiO2 nanorods as electron transport pathway for high performance perovskite solar cells. Nano Res. 2019, 12, 601–606.

    Article  CAS  Google Scholar 

  28. Pan, B.; Gu, J. H.; Xu, X. L.; Xiao, L. B.; Zhao, J.; Zou, G. F. Interface engineering of high performance all-inorganic perovskite solar cells via low-temperature processed TiO2 nanopillar arrays. Nano Res. 2021, 14, 3431–3438.

    Article  CAS  Google Scholar 

  29. Rathee, D.; Arya, S. K.; Kumar, M. Analysis of TiO2 for microelectronic applications: Effect of deposition methods on their electrical properties. Front. Optoelectron. China 2011, 4, 349–358.

    Article  Google Scholar 

  30. Aglieri, V.; Zaffora, A.; Lullo, G.; Santamaria, M.; Di Franco, F.; Lo Cicero, U.; Mosca, M.; Macaluso, R. Resistive switching in microscale anodic titanium dioxide-based memristors. Superlattices Microstruct. 2018, 113, 135–142.

    Article  CAS  Google Scholar 

  31. Mosca, M.; Macaluso, R.; Randazzo, G.; Di Bella, M.; Caruso, F.; Calì, C.; Di Franco, F.; Santamaria, M.; Di Quarto, F. Anodized Ti-Si alloy as gate oxide of electrochemically-fabricated organic field-effect transistors. ECS Solid State Lett. 2014, 3, 7–9.

    Article  Google Scholar 

  32. Ji, T.; He, S. Q.; Ai, F. J.; Wu, J. H.; Yan, L.; Hu, J. Q.; Liao, M. Y. An adjustable multi-color detector based on regulating TiO2 surface adsorption and multi-junction synergy. Nano Res. 2021, 14, 3423–3430.

    Article  CAS  Google Scholar 

  33. Li, Y. B.; Cooper, J. K.; Liu, W. J.; Sutter-Fella, C. M.; Amani, M.; Beeman, J. W.; Javey, A.; Ager, J. W.; Liu, Y.; Toma, F. M. et al. Defective TiO2 with high photoconductive gain for efficient and stable planar heterojunction perovskite solar cells. Nat. Commun. 2016, 7, 12446.

    Article  CAS  Google Scholar 

  34. Lewis, A.; Troughton, J. R.; Smith, B.; McGettrick, J.; Dunlop, T.; De Rossi, F.; Pockett, A.; Spence, M.; Carnie, M. J.; Watson, T. M. et al. In-depth analysis of defects in TiO2 compact electron transport layers and impact on performance and hysteresis of planar perovskite devices at low light. Sol. Energy Mater. Sol. Cells 2020, 209, 110448.

    Article  CAS  Google Scholar 

  35. Messmer, C.; Bivour, M.; Schön, J.; Glunz, S. W.; Hermle, M. Numerical simulation of silicon heterojunction solar cells featuring metal oxides as carrier-selective contacts. IEEE J. Photovoltaics 2018, 8, 456–464.

    Article  Google Scholar 

  36. Shen, H. P.; Omelchenko, S. T.; Jacobs, D. A.; Yalamanchili, S.; Wan, Y. M.; Yan, D.; Phang, P.; Duong, T.; Wu, Y. L.; Yin, Y. T. et al. In situ recombination junction between P-Si and TiO2 enables high-efficiency monolithic perovskite/Si tandem cells. Sci. Adv. 2018, 4, eaau9711.

    Article  CAS  Google Scholar 

  37. Vaněček, M.; Kočka, J.; Stuchlík, J.; Kožíšek, Z.; Štika, O.; Tříska, A. Density of the gap states in undoped and doped glow discharge ASi: H. Sol. Energy Mater. 1983, 8, 411–423.

    Article  Google Scholar 

  38. KočKa, J.; Vaněček, M.; TříSka, A. Energy and density of gap states in a-Si:H. In Amorphous Silicon and Related Materials; Fritzsche, H., Ed.; World Scientific: Singapore, 1989; pp 297–327.

    Chapter  Google Scholar 

  39. Morawiec, S.; Holovský, J.; Mendes, M. J.; Müller, M.; Ganzerová, K.; Vetushka, A.; Ledinský, M.; Priolo, F.; Fejfar, A.; Crupi, I. Experimental quantification of useful and parasitic absorption of light in plasmon-enhanced thin silicon films for solar cells application. Sci. Rep. 2016, 6, 22481.

    Article  CAS  Google Scholar 

  40. Scirè, D.; Procel, P.; Gulino, A.; Isabella, O.; Zeman, M.; Crupi, I. Sub-gap defect density characterization of molybdenum oxide: An annealing study for solar cell applications. Nano Res. 2020, 13, 3416–3424.

    Article  Google Scholar 

  41. Scirè, D.; Macaluso, R.; Mosca, M.; Mirabella, S.; Gulino, A.; Isabella, O.; Zeman, M.; Crupi, I. Characterization of the defect density states in MoOx for C-Si solar cell applications. Solid State Electron. 2021, 185, 108135.

    Article  Google Scholar 

  42. Sherwood, P. M. A. Data analysis in X-ray photoelectron spectroscopy. In Practical surface analysis by Auger and X-ray Photoelectron Spectroscopy; Briggs, D.; Seah, M. P., Eds.; John Wiley and Sons: Chichester, 1983; pp 445–475.

    Google Scholar 

  43. Wagner, C. D.; Davis, L. E.; Riggs, W. M. The energy dependence of the electron mean free path. Surf. Interface Anal. 1980, 2, 53–55.

    Article  CAS  Google Scholar 

  44. Alexander V. Naumkin, A. V.; Kraut-Vass, A.; Gaarenstroom, S. W.; Powell, C. J. NISTX-ray Photoelectron Spectroscopy Database, NIST Standard Reference Database 20, Version 4.1; National Institute of Standards and Technology: Gaithersburg MD, 2000. https://srdata.nist.gov/xps/ (accessed Jul 1, 2021).

    Google Scholar 

  45. Remes, Z.; Vasudevan, R.; Jarolimek, K.; Smets, A. H. M.; Zeman, M. The optical spectra of a-Si:H and a-SiC:H thin films measured by the absolute photothermal deflection spectroscopy (PDS). Solid State Phenom. 2014, 213, 19–28.

    Article  Google Scholar 

  46. Singh, M.; Santbergen, R.; Mazzarella, L.; Madrampazakis, A.; Yang, G.; Vismara, R.; Remes, Z.; Weeber, A.; Zeman, M.; Isabella, O. Optical characterization of poly-SiOx and poly-SiCx carrier-selective passivating contacts. Sol. Energy Mater. Sol. Cells 2020, 210, 110507.

    Article  CAS  Google Scholar 

  47. Zhao, Y. F.; Mazzarella, L.; Procel, P.; Han, C.; Yang, G. T.; Weeber, A.; Zeman, M.; Isabella, O. Doped hydrogenated nanocrystalline silicon oxide layers for high-efficiency c-Si heterojunction solar cells. Prog. Photovoltaics Res. Appl. 2020, 28, 425–435.

    Article  CAS  Google Scholar 

  48. Bharti, B.; Kumar, S.; Lee, H. N.; Kumar, R. Formation of oxygen vacancies and Ti3+ state in TiO2 thin film and enhanced optical properties by air plasma treatment. Sci. Rep. 2016, 6, 32355.

    Article  CAS  Google Scholar 

  49. Sanjinés, R.; Tang, H.; Berger, H.; Gozzo, F.; Margaritondo, G.; Lévy, F. Electronic structure of anatase TiO2 oxide. J. Appl. Phys. 1994, 75, 2945–2951.

    Article  Google Scholar 

  50. Gouttebaron, R.; Cornelissen, D.; Snyders, R.; Dauchot, J. P.; Wautelet, M.; Hecq, M. XPS study of TiOx thin films prepared by d. c. magnetron sputtering in Ar-O2 gas mixtures. Surf. Interface Anal. 2000, 30, 527–530.

    Article  CAS  Google Scholar 

  51. Akl, A. A.; Kamal, H.; Abdel-Hady, K. Fabrication and characterization of sputtered titanium dioxide films. Appl. Surf. Sci. 2006, 252, 8651–8656.

    Article  CAS  Google Scholar 

  52. Zhang, J. Y.; Boyd, I. W.; O’Sullivan, B. J.; Hurley, P. K.; Kelly, P. V.; Sénateur, J. P. Nanocrystalline TiO2 films studied by optical, XRD and FTIR spectroscopy. J. Non. Cryst. Solids 2002, 303, 134–138.

    Article  CAS  Google Scholar 

  53. Katagiri, K.; Suzuki, T.; Muto, H.; Sakai, M.; Matsuda, A. Low temperature crystallization of TiO2 in layer-by-layer assembled thin films formed from water-soluble Ti-complex and polycations. Colloids Surfaces A Physicochem. Eng. Aspects 2008, 321, 233–237.

    Article  CAS  Google Scholar 

  54. Matthews, A. The crystallization of anatase and rutile from amorphous titanium dioxide under hydrothermal conditions. Am. Mineral. 1976, 61, 419–424.

    CAS  Google Scholar 

  55. Bakri, A. S.; Sahdan, M. Z.; Adriyanto, F.; Raship, N. A.; Said, N. D. M.; Abdullah, S. A.; Rahim, M. S. Effect of annealing temperature of titanium dioxide thin films on structural and electrical properties. AIP Conf. Proc. 2017, 1788, 030030.

    Article  Google Scholar 

  56. Zhang, Q.; Ma, L. S.; Shao, M. H.; Huang, J. Z.; Ding, M.; Deng, X. L.; Wei, X. Q.; Xu, X. J. Anodic oxidation synthesis of one-dimensional TiO2 nanostructures for photocatalytic and field emission properties. J. Nanomater. 2014, 2014, 831752.

    Article  Google Scholar 

  57. Stagi, L.; Carbonaro, C. M.; Corpino, R.; Chiriu, D.; Ricci, P. C. Light induced TiO2 phase transformation: Correlation with luminescent surface defects. Phys. Status Solidi Basic Res. 2015, 252, 124–129.

    Article  CAS  Google Scholar 

  58. Rajaraman, T. S.; Parikh, S. P.; Gandhi, V. G. Black TiO2: A review of its properties and conflicting trends. Chem. Eng. J. 2020, 389, 123918.

    Article  CAS  Google Scholar 

  59. Zhu, G. Y.; Ma, L. B.; Lin, H. N.; Zhao, P. Y.; Wang, L.; Hu, Y.; Chen, R. P.; Chen, T.; Wang, Y. R.; Tie, Z. X. et al. Highperformance Li-ion capacitor based on black-TiO2−x/graphene aerogel anode and biomass-derived microporous carbon cathode. Nano Res. 2019, 12, 1713–1719.

    Article  CAS  Google Scholar 

  60. Daniel, L. S.; Nagai, H.; Yoshida, N.; Sato, M. Photocatalytic activity of vis-responsive Ag-nanoparticles/TiO2 composite thin films fabricated by molecular precursor method (MPM). Catalysts 2013, 3, 625–645.

    Article  Google Scholar 

  61. Koster, G.; Blank, D. H. A.; Rijnders, G. A. J. H. M. Oxygen in complex oxide thin films grown by pulsed laser deposition: A perspective. J. Supercond. Nov. Magn. 2020, 33, 205–212.

    Article  CAS  Google Scholar 

  62. Tauc, J.; Grigorovici, R.; Vancu, A. Optical properties and electronic structure of amorphous germanium. Phys. Status Solidi 1966, 15, 627–637.

    Article  CAS  Google Scholar 

  63. Urbach, F. The long-wavelength edge of photographic sensitivity and of the electronic absorption of solids. Phys. Rev. 1953, 92, 1324.

    Article  CAS  Google Scholar 

  64. Zhong, Q.; Vohs, J. M.; Bonnell, D. A. Effect of reduction on the topographic and electronic structure of TiO2(110) surfaces. Surf. Sci. 1992, 274, 35–43.

    Article  CAS  Google Scholar 

  65. Choudhury, B.; Choudhury, A. Oxygen defect dependent variation of band gap, urbach energy and luminescence property of anatase, anatase-rutile mixed phase and of rutile phases of TiO2 nanoparticles. Phys. E Low-Dimensional Syst. Nanostructures 2014, 56, 364–371.

    Article  CAS  Google Scholar 

  66. Bouizem, Y.; Belfedal, A.; Sib, J. D.; Chahed, L. Density of states in hydrogenated amorphous germanium seen via optical absorption spectra. Solid State Commun. 2003, 126, 675–680.

    Article  CAS  Google Scholar 

  67. Kormann, C.; Bahnemann, D. W.; Hoffmann, M. R. Preparation and characterization of quantum-size titanium dioxide. J. Phys. Chem. 1988, 92, 5196–5201.

    Article  CAS  Google Scholar 

  68. Jackson, W. B.; Kelso, S. M.; Tsai, C. C.; Allen, J. W.; Oh, S. J. Energy dependence of the optical matrix element in hydrogenated amorphous and crystalline silicon. Phys. Rev. B 1985, 31, 5187–5198.

    Article  CAS  Google Scholar 

  69. Gulino, A.; Tabbì, G. CdO thin films: A study of their electronic structure by electron spin resonance spectroscopy. Appl. Surf. Sci. 2005, 245, 322–327.

    Article  CAS  Google Scholar 

  70. Deb, S. K.; Chopoorian, J. A. Optical properties and color-center formation in thin films of molybdenum trioxide. J. Appl. Phys. 1966, 37, 4818–4825.

    Article  CAS  Google Scholar 

  71. Ederth, J.; Hoel, A.; Niklasson, G. A.; Granqvist, C. G. Small polaron formation in porous WO3−x nanoparticle films. J. Appl. Phys. 2004, 96, 5722–5726.

    Article  CAS  Google Scholar 

  72. Niklasson, G. A.; Klasson, J.; Olsson, E. Polaron absorption in tungsten oxide nanoparticle aggregates. Electrochim. Acta 2001, 46, 1967–1971.

    Article  CAS  Google Scholar 

  73. Dieterle, M.; Weinberg, G.; Mestl, G. Raman spectroscopy of molybdenum oxides-Part I. Structural characterization of oxygen defects in MoO3−x by DR UV/VIS, Raman spectroscopy and X-ray diffraction. Phys. Chem. Chem. Phys. 2002, 4, 812–821.

    Article  CAS  Google Scholar 

  74. Chen, J.; Bogdanov, N. A.; Usvyat, D.; Fang, W.; Michaelides, A.; Alavi, A. The color center singlet state of oxygen vacancies in TiO2. J. Chem. Phys. 2020, 153, 204704.

    Article  CAS  Google Scholar 

  75. Reticcioli, M.; Diebold, U.; Kresse, G.; Franchini, C. Small Polarons in Transition Metal Oxides. In Handbook of Materials Modeling; Andreoni, W.; Yip, S., Eds.; Springer, Cham, 2019.

    Google Scholar 

  76. Moses, P. G.; Janotti, A.; Franchini, C.; Kresse, G.; Van De Walle, C. G. donor defects and small polarons on the TiO2(110) surface. J. Appl. Phys. 2016, 119, 181503.

    Article  Google Scholar 

  77. Colton, R. J.; Guzman, A. M.; Rabalais, J. W. Photochromism and electrochromism in amorphous transition metal oxide films. Acc. Chem. Res. 1978, 11, 170–176.

    Article  CAS  Google Scholar 

  78. Austin, I. G.; Mott, N. F. Polarons in crystalline and non-crystalline materials. Adv. Phys. 2001, 50, 757–812.

    Article  Google Scholar 

  79. Zaynobidinov, S.; Ikramov, R. G.; Jalalov, R. M. Urbach energy and the tails of the density of states in amorphous semiconductors. J. Appl. Spectrosc. 2011, 78, 223–227.

    Article  CAS  Google Scholar 

  80. Nakano, Y.; Morikawa, T.; Ohwaki, T.; Taga, Y. Origin of visible-light sensitivity in N-doped TiO2 films. Chem. Phys. 2007, 339, 20–26.

    Article  CAS  Google Scholar 

  81. Freysoldt, C.; Grabowski, B.; Hickel, T.; Neugebauer, J.; Kresse, G.; Janotti, A.; Van De Walle, C. G. First-principles calculations for point defects in solids. Rev. Mod. Phys. 2014, 86, 253–305.

    Article  Google Scholar 

  82. Umebayashi, T.; Yamaki, T.; Itoh, H.; Asai, K. Analysis of electronic structures of 3d transition metal-doped TiO2 based on band calculations. J. Phys. Chem. Solids 2002, 63, 1909–1920.

    Article  CAS  Google Scholar 

  83. Mudgal, S.; Nayak, M.; Singh, S.; Komarala, V. K. Study of anomalous S-shape in current density-voltage characteristics of carrier selective contact molybdenum oxide and amorphous silicon based heterojunction silicon solar cells. AIP Conf. Proc. 2019, 2147, 020009.

    Article  Google Scholar 

  84. Saive, R. S-shaped current-voltage characteristics in solar cells: A review. IEEE J. Photovoltaics 2019, 9, 1477–1484.

    Article  Google Scholar 

  85. Di Piazza, M. C.; Luna, M.; Vitale, G. Dynamic PV model parameter identification by least-squares regression. IEEE J. Photovoltaics 2013, 3, 799–806.

    Article  Google Scholar 

  86. García-Sánchez, F. J.; Lugo-Muñoz, D.; Muci, J.; Ortiz-Conde, A. Lumped parameter modeling of organic solar cells’ S-shaped I-V characteristics. IEEE J. Photovoltaics 2013, 3, 330–335.

    Article  Google Scholar 

  87. Aghassi, A.; Fay, C. D.; Mozer, A. Investigation of S-shaped current-voltage characteristics in high-performance solution-processed small molecule bulk heterojunction solar cells. Org. Electron. 2018, 62, 133–141.

    Article  CAS  Google Scholar 

  88. Zuo, L. J.; Yao, J. Z.; Li, H. Y.; Chen, H. Z. Assessing the origin of the S-shaped I-V curve in organic solar cells: An improved equivalent circuit model. Sol. Energy Mater. Sol. Cells 2014, 122, 88–93.

    Article  CAS  Google Scholar 

  89. Corless, R. M.; Gonnet, G. H.; Hare, D. E. G.; Jeffrey, D. J.; Knuth, D. E. On the lambert W function. Adv. Comput. Math. 1996, 5, 329–359.

    Article  Google Scholar 

  90. Breitenstein, O.; Bauer, J.; Altermatt, P. P.; Ramspeck, K. Influence of defects on solar cell characteristics. Solid State Phenom. 2009, 156-158, 1–10.

    Article  Google Scholar 

Download references

Acknowledgements

We thank A. Nicolosi for the assistance with the PLD deposition, M. Bonadonna for the assistance with the XPS analysis and Y. Zhao for the assistance with the solar cell prototype manufacturing.

Author information

Authors and Affiliations

  1. Department of Engineering, University of Palermo, Viale dette Scienze, Ed. 9, Palermo, 90128, Italy

    Daniele Scirè, Roberto Macaluso, Mauro Mosca & Isodiana Crupi

  2. Institute of Nanostructured Materials (ISMN), National Research Council (CNR), Via Ugo La Malfa 153, Palermo, 90146, Italy

    Maria Pia Casaletto

  3. Photovoltaic Materials and Devices Group, Delft University of Technology, Mekelweg 4, Delft, 2628CD, the Netherlands

    Olindo Isabella & Miro Zeman

Authors
  1. Daniele Scirè
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Roberto Macaluso
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Mauro Mosca
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Maria Pia Casaletto
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Olindo Isabella
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Miro Zeman
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Isodiana Crupi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Daniele Scirè.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Scirè, D., Macaluso, R., Mosca, M. et al. Density of states characterization of TiO2 films deposited by pulsed laser deposition for heterojunction solar cells. Nano Res. 15, 4048–4057 (2022). https://doi.org/10.1007/s12274-021-3985-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12274-021-3985-8

Keywords

Search

Navigation