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Arabian Journal for Science and Engineering

, Volume 44, Issue 1, pp 603–612 | Cite as

Bandgap Engineering in \(\hbox {TiO}_{2}\)–Ge Nanocomposite Thin Films

  • Asma Nazir
  • Ehsan Ullah Khan
  • Ali Nadeem
  • Arshad Mahmood Janjua
  • Ahmed Shuja Syed
  • Shaista ShahzadaEmail author
Research Article - Physics
  • 9 Downloads

Abstract

Titanium dioxide–germanium (\(\hbox {TiO}_{2}\)–Ge) composite thin films were prepared by pulse laser deposition technique using third harmonic (355 nm) of Nd:YAG laser at fluence of \(12.73\,\hbox {J/cm}^{2}\). Films were grown on n-type Si (100) substrate using \(\hbox {TiO}_{2}\)–Ge composite target. The bandgap was tailored by varying the composition of \(\hbox {TiO}_{2}\)–Ge composite films based on the variable substrate–target distance from 5–8 cm. Ge concentration in \(\hbox {TiO}_{2}\) matrix was measured through electron-dispersive X-ray spectroscopy and concentration variation from 0.9–25.3% was observed. Crystalline structure of thin films was analysed through X-ray diffraction, whereas micro-strains and dislocation density is also calculated through different X-ray diffraction peaks. A detailed study of the various polymorphs of \(\hbox {TiO}_{2}\) and presence of Ge in crystalline form was carried out through Raman spectroscopy. Direct and indirect absorption transitions were observed through ultraviolet and visible spectroscopy. Absorption edge shifted to visible region of electromagnetic spectrum is associated with a possible quantum confinement effect in Ge or strain generated due to lattice mismatch of Si substrate and Ge with \(\hbox {TiO}_{2}\). Absorption transitions of thin film containing 2.6% Ge were observed in visible region along with the emission in the same spectral region observed through photoluminescence spectra.

Keywords

Pulsed laser deposition (PLD) \(\hbox {TiO}_{2}\)–Ge composites Raman spectroscopy X-ray diffraction Band-gap engineering 

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Notes

Acknowledgements

Thin Films and Laser Spectroscopy Labs at NILOP, Advance Characterization Lab at NILOP, XRD lab at COMSATS Institute of Information Technology, FESEM lab at Institute of Space Technology, Advance Electronics Laboratories at International Islamic University are acknowledged for variety of facility access and continued support to this work. Dr Manzar Abbas from COMSATS Institute of Information Technology is also acknowledged to provide us with wafers used in our experiment. Higher Education Commission, Pakistan is also acknowledged for awarding indigenous scholarship to PhD scholar Ms. Asma Nazir (HEC Pin # 063-112702-PS3-114).

References

  1. 1.
    Smith, A.M.; Nie, S.: Semiconductor nanocrystals: structure, properties and bandgap engineering. Acc. Chem. Res. 43(2), 190–200 (2010)Google Scholar
  2. 2.
    López-Luke, T.; Wolcott, A.; Xu, L.-P.; Chen, S.; Wen, Z.; Li, J.; De La Rosa, E.; Zhang, J.Z.: Nitrogen-doped and CdSe quantum-dot-sensitized nanocrystalline \(\text{ TiO }_{2}\) films for solar energy conversion applications. J. Phys. Chem. C 112, 1282–1292 (2008)Google Scholar
  3. 3.
    Zhao, J.P.; Huang, D.X.; Chen, Z.Y.; Chu, W.K.; Makarenkov, B.; Jacobson, A.J.; Bahrim, B.; Rabalais, J.W.: Amorphous Ge quantum dots embedded in SiO\(_2\) formed by low energy ion implantation. J. Appl. Phys. 103(12), 124304 (2008)Google Scholar
  4. 4.
    Asahi, R.; Morikawa, T.; Ohwaki, T.; Aoki, K.; Taga, Y.: Visible-light photocatalysis in nitrogen-doped titanium oxides. Science 293(5528), 269–271 (2001)Google Scholar
  5. 5.
    Abbas, M.; Ali, B.; Shah, S.I.; Akhter, P.: Germanium quantum dot sensitized \(\text{ TiO }_{2}\) solar cells. Key Eng. Mater. 442, 404–414 (2010)Google Scholar
  6. 6.
    Li, X.; He, F.; Liu, G.; Huang, Y.; Pan, C.; Guo, C.: Fabrication of Ge quantum dots doped \(\text{ TiO }_{2}\) films with high optical absorption properties via layer-by-layer ion-beam sputtering. Mater. Lett. 67(1), 369–372 (2012)Google Scholar
  7. 7.
    Adán, C.; Bahamonde, A.; Fernández-García, M.; Martínez-Arias, A.: Structure and activity of nanosized iron-doped anatase \(\text{ TiO }_{2}\) catalysts for phenol photocatalytic degradation. Appl. Catal. B Environ. 72(1–2), 11–17 (2007)Google Scholar
  8. 8.
    Dang, C.; Lee, J.; Breen, C.; Steckel, J.S.; Coe-Sullivan, S.; Nurmikko, A.: Red, green and blue lasing enabled by single-exciton gain in colloidal quantum dot films. Nat. nanotechnol. 7(5), 335–339 (2012)Google Scholar
  9. 9.
    Mahler, B.; Lequeux, N.; Dubertret, B.: Ligand-controlled polytypism of thick-shell CdSe/CdS nanocrystals. J. Am. Chem. Soc. 132(3), 953–959 (2010)Google Scholar
  10. 10.
    Jeong, S.; Yoo, D.; Jang, J.T.; Kim, M.; Cheon, J.: Well-defined colloidal 2-D layered transition-metal chalcogenide nanocrystals via generalized synthetic protocols. J. Am. Chem. Soc. 134(44), 18233–18236 (2012)Google Scholar
  11. 11.
    Cao, Y.; He, T.; Chen, Y.; Cao, Y.: Fabrication of rutile \(\text{ TiO }_{2}\)-Sn/anatase \(\text{ TiO }_{2}\)-N heterostructure and its application in visible-light photocatalysis. J. Phys. Chem. C 114(8), 3627–3633 (2010)Google Scholar
  12. 12.
    Chatterjee, S.: Titania–germanium nanocomposite as a photovoltaic material. Sol. Energy 82(2), 95–99 (2008)Google Scholar
  13. 13.
    Khan, A.F.; Mehmood, M.; Aslam, M.; Shah, S.I.: Nanostructured multilayer \(\text{ TiO }_{2}\)–Ge films with quantum confinement effects for photovoltaic applications. J. Colloid Interface Sci. 343(1), 271–280 (2010)Google Scholar
  14. 14.
    Burda, C.; Lou, Y.; Chen, X.; Samia, A.C.S.; Stout, J.; Gole, J.L.: Enhanced nitrogen doping in \(\text{ TiO }_{2}\) nanoparticles. Nano Lett. 3(8), 1049–1051 (2003)Google Scholar
  15. 15.
    Zaleska, A.: Doped-TiO\(_2\): a review. Recent Patents Eng. 2(3), 157–164 (2008)Google Scholar
  16. 16.
    Anpo, M.: Use of visible light. Second-generation titanium oxide photocatalysts prepared by the application of an advanced metal ion-implantation method. Pure Appl. Chem. 72(9), 1787–1792 (2000)Google Scholar
  17. 17.
    Yu, J.C.; Zhang, L.; Zheng, Z.; Zhao, J.: Synthesis and characterization of phosphated mesoporous titanium dioxide with high photocatalytic activity. Chem. Mater. 15(11), 2280–2286 (2003)Google Scholar
  18. 18.
    Štengl, V.; Henych, J.; Št’astný, M.; Kormunda, M.: Fast and straightforward synthesis of luminescent titanium(IV) dioxide quantum dots. J. Nanomater. 2017, 1–9 (2017)Google Scholar
  19. 19.
    Sun, Y.P.; Zhou, B.; Lin, Y.; Wang, W.; Fernando, K.A.; Pathak, P.; Meziani, M.J.; Harruff, B.A.; Wang, X.; Wang, H.; Luo, P.G.; Yang, H.; Kose, M.E.; Chen, B.; Veca, L.M.; Xie, S.Y.: Quantum-sized carbon dots for bright and colorful photoluminescence. J. Am. Chem. Soc. 128(24), 7756–7757 (2006)Google Scholar
  20. 20.
    Yoffe, A.D.: Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems. Adv. Phys. 51(2), 799–890 (2010)Google Scholar
  21. 21.
    Nozik, A.J.: Quantum dot solar cells. Physica E 14, 115–120 (2002)Google Scholar
  22. 22.
    Chatterjee, S.; Goyal, A.; Shah, S.I.: Inorganic nanocomposites for the next generation photovoltaics. Mater. Lett. 60(29), 3541–3543 (2006)Google Scholar
  23. 23.
    Chatterji, S.; Chatterji, A.: Optoelectronic properties of Ge-doped \(\text{ TiO }_{2}\) nanoparticles. Jpn. J. Appl. Phys. 47(2), 1136–1139 (2008)Google Scholar
  24. 24.
    Shahzada, S.; Fatima, A.; Nazir, A.; Mehmood, A.; Mehmood, M.; Nadeem, A.: Structural and optical properties of \(\text{ TiO }_{2}\)–Ge nanoparticles prepared through laser ablation in liquid medium. Can. J. Phys. 95(7), 645–649 (2017)Google Scholar
  25. 25.
    Abe, S.; Ohnuma, M.; Ping, D.H.; Ohnumaand, S.: Anatase dominent matrix in Ge/ \(\text{ TiO }_{2}\) thin films prepared by RF sputtering method. Appl. Phys. Exp. 1, 095001\_095001-095003 (2008)Google Scholar
  26. 26.
    Ibrahim, A.S.; Khan, A.F.; Razak, B.B.A.: \(\text{ Ge/TiO }_{2}\) composite thin films prepared by RF magnetron sputtering for Photovoltaic Applications. Paper presented at the \(3^{{\rm RD}}\) IET International Conference on Clean Energy and Technology (CEAT) 2014, Kuching, 24–26 NovGoogle Scholar
  27. 27.
    Biswas, D.; Biswas, J.; Ghosh, S.; Wood, B.; Lodha, S.: Enhanced thermal stability of Ti/TiO\(_2\)/n–Ge contacts through plasma nitridation of TiO\(_2\) interfacial layer. Appl. Phys. Lett. 110(5), 052104 (2017)Google Scholar
  28. 28.
    Sadeghi, H.; Zolanvar, A.; Ranjgar, A.; Norouzi, R.: Effective Permittivity and refractive index of TiO\(_2\)/Ge and SiO\(_2\)/Ge nanostructures at high frequencies. J. Electron. Mater. 43(11), 4294–4300 (2014)Google Scholar
  29. 29.
    Suzuki, Y.; Nagata, T.; Yamashita, Y.; Nabatame, T.; Ogura, A.; Chikyow, T.: Effect of Y and Mn doping into rutile type TiO\(_2\)/Ge stack structure by combinatorial synthesis. Jpn. J. Appl. Phys. 56(6S1), 06GF11 (2017)Google Scholar
  30. 30.
    Cha, J.O.; Nam, T.H.; Alghusun, M.: Composition and crystalline properties of TiNi thin films prepared by pulsed laser deposition under vacuum and in ambient Ar gas. Nanoscale Res. Lett. 37(1), 7 (2012)Google Scholar
  31. 31.
    Mostako, A.T.T.; Khare, A.: Effect of target–substrate distance onto the nanostructured rhodium thin films via PLD technique. Appl. Nanosci. 2(3), 189–193 (2012)Google Scholar
  32. 32.
    Rawat, K.; Dhruvashi,; Shishodia, P.K.: Role of target–substrate distance on the growth of \(\text{ CuInSe }_{2}\) thin films by pulsed laser ablation technique. AIP Conf. Proc. 1728, 020253 (2016)Google Scholar
  33. 33.
    Masa, J.A.D.; Amo, A.M.; Miranda, J.J.C.; Salazar, H.O.; Sarmago, R.V.; Garcia, W.O.: Effects of deposition pressure and target–substrate distance on growth of ZnO by femtosecond pulsed laser deposition. J. Laser. Micro/Nanoeng. 11(1), 21–24 (2016)Google Scholar
  34. 34.
    Debelo, N.G.; Dejene, F.B.; Roro, K.T.: Pulsed laser deposited \(\text{ KY }_{3} \text{ F }_{10}:\text{ Ho }^{3+}\) thin films: influence of target to substrate distance. Mater. Chem. Phys. 190, 62–67 (2017)Google Scholar
  35. 35.
    Yang, W.; Wang, W.; Lin, Y.; Zhou, S.; Liu, Y.; Li, G.: Effect of target–substrate distance on the quality of AlN films grown on Si(110) substrates by pulsed laser deposition. Mater. Lett. 160, 20–23 (2015)Google Scholar
  36. 36.
    Ashfold, M.N.R.; Claeyssens, F.; Fuge, G.M.; Henley, S.J.: Pulsed laser ablation and deposition of thin films. Chem. Soc. Rev. 33(1), 23–31 (2004)Google Scholar
  37. 37.
    Aydın, C.; Abd El-sadek, M.S.; Zheng, K.; Yahia, I.S.; Yakuphanoglu, F.: Synthesis, diffused reflectance and electrical properties of nanocrystalline Fe-doped ZnO via sol–gel calcination technique. Opt. Laser. Technol. 48, 447–452 (2013)Google Scholar
  38. 38.
    Arnold, C.B.; Aziz, M.J.: Stoichiometry issues in pulsed-laser deposition of alloys grown from multicomponent targets. Appl. Phys. A Mater. Sci. Proc. 69(S1), S23–S27 (1999)Google Scholar
  39. 39.
    Willmoti, P.R.; Huber, J.R.: Pulsed laser vaporization and deposition. Rev. Mod. Phys. 72, 315 (2000)Google Scholar
  40. 40.
    Venkatesan, T.: Pulsed laser deposition–invention or discovery? J. Phys. D Appl. Phys. 47(3), 034001 (2014)Google Scholar
  41. 41.
    Zhao, Y.; Zhang, J.: Microstrain and grain-size analysis from diffraction peak width and graphical derivation of high-pressure thermomechanics. J. Appl. Crystallogr. 41(6), 1095–1108 (2008)Google Scholar
  42. 42.
    Díaz-Reyes, J.; Castillo-Ojeda, R.S.; Flores-Mena, J.E.; Martínez-Juárez, J.: Structural and optical characterization of ZnO nanofilms deposited by CBD-A\(\mu \)W. MRS Proc. 1766, 151–158 (2015)Google Scholar
  43. 43.
    Moosakhani, S.; Sabbagh Alvani, A.A.; Sarabi, A.A.; Sameie, H.; Salimi, R.; Kiani, S.; Ebrahimi, Y.: Non-toxic silver iodide (AgI) quantum dots sensitized solar cells. Mater. Res. Bull. 60, 38–45 (2014)Google Scholar
  44. 44.
    Hamzaoui, N.; Boukhachem, A.; Ghamnia, M.; Fauquet, C.: Investigation of some physical properties of ZnO nanofilms synthesized by micro-droplet technique. Results Phys. 7, 1950–1958 (2017)Google Scholar
  45. 45.
    Olivares, J.; Martın, P.; Rodrıguez, A.; Sangrador, J.; Jiménez, J.; Rodrıguez, T.: Raman spectroscopy study of amorphous SiGe films deposited by low pressure chemical vapour deposition and polycrystalline SiGe films obtained by solid-phase crystallization. Thin Solid Films 358(1), 56–61 (2000)Google Scholar
  46. 46.
    Jafarkhani, P.; Dadras, S.; Torkamany, M.J.; Sabbaghzadeh, J.: Synthesis of nanocrystalline titania in pure water by pulsed Nd:YAG Laser. Appl. Surf. Sci. 256, 5 (2010)Google Scholar
  47. 47.
    Iliev, M.N.; Hadjiev, V.G.; Litvinchuk, A.P.: Raman and infrared spectra of brookite (\(\text{ TiO }_{2}\)): experiment and theory. Vib. Spectrosc. 64, 148–152 (2013)Google Scholar
  48. 48.
    Welte, A.; Waldauf, C.; Brabec, C.; Wellmann, P.J.: Application of optical absorbance for the investigation of electronic and structural properties of sol–gel processed \(\text{ TiO }_{2}\) films. Thin Solid Films 516(20), 7256–7259 (2008)Google Scholar
  49. 49.
    Džimbeg-Malčić, V.; Barbarić-Mikočević, Ž.; Itrić, K.: Kubelka–Munk theory in describing optical properties of paper (I). Tech. Gaz. 18(1), 117–124 (2011)Google Scholar
  50. 50.
    Sze, S.M.; Ng, K.K.: Physics of Semiconductor Devices. Wiley, New York (2006)Google Scholar
  51. 51.
    Goyal, A.; Rumaiz, A.K.; Miao, Y.; Hazra, S.; Ni, C.; Shah, S.I.: Synthesis and characterization of Ti \(\text{ O }_{2}\)–Ge nanocomposites. J. Vac. Sci. Technol. 26(4), 1315–1320 (2008)Google Scholar
  52. 52.
    Arguirov, T.; Kittler, M.; Abrosimov, N.V.: Room temperature luminescence from germanium. J. Phys. Conf. Ser. 281(1), 012021 (2011)Google Scholar
  53. 53.
    Jawad, M.J.; Hashim, M.R.; Ali, N.K.; Corcoles, E.P.; Arora, V.K.: Photoluminescence of ultraviolent initiated green emission from electrochemically deposited germanium films on (100) silicon. J. Electrochem. Soc. 161(14), D801–D805 (2014)Google Scholar
  54. 54.
    Sun, K.W.; Sue, S.H.; Liu, C.W.: Visible photoluminescence from Ge quantum dots. Phys. E Low Dimens. Syst. Nanostruct. 28(4), 525–530 (2005)Google Scholar
  55. 55.
    Kaganovich, E.B.; Korbutyak, D.V.; Kryuchenko, Y.V.; Kupchak, I.M.; Manoilov, E.G.; Sachenko, A.V.: Exciton states and photoluminescence in Ge quantum dots. Nanotechnology 18(29), 295401 (2007)Google Scholar

Copyright information

© King Fahd University of Petroleum & Minerals 2018

Authors and Affiliations

  1. 1.Department of PhysicsInternational Islamic UniversityIslamabadPakistan
  2. 2.National Institute of Laser and Optronics (NILOP)IslamabadPakistan
  3. 3.Advanced Electronics Labs. (AEL)International Islamic UniversityIslamabadPakistan

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