Skip to main content
SpringerLink
Log in

Thermal evolution of physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cells

  • Published:
Journal of Materials Science: Materials in Electronics Aims and scope Submit manuscript

Abstract

This paper reports the change in optical, structural, morphological and electrical properties of CdTe thin films with post-deposition thermal treatment in air atmosphere. The polycrystalline cadmium telluride (CdTe) thin films of thickness 850 nm were deposited on glass and ITO coated glass substrates by thermal vacuum evaporation technique followed by annealing at different temperature 150, 250 and 350 °C. The physical properties have been investigated using characterization tools like UV–Vis spectrophotometer, X-ray diffraction, scanning electron microscopy coupled with EDS and source meter. The optical transmittance was observed to increase with post-deposition heat treatment which revealed the systematic reduction in optical energy band gap from 1.78 to 1.54 eV. The Swanepoel and Herve–Vandamme models as well as the dielectric theory were used to calculate various optical and dielectric constants. The thermal annealing enhances the crystallinity (zinc blende cubic structure) of films with preferred orientation (111). A number of crystallographic parameters were also evaluated and studied in depth with heat treatment. The surface morphology studies indicate that the films are homogeneous, densely packed, uniform and free from crystal defects. The current–voltage measurements exhibited ohmic behavior and the conductivity was found to increase with annealing temperature.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

References

  1. H. Hernandez-Contreras, G. Contreras-Puente, J. Aguilar-Hernandez, A. Morales-Acevedo, J. Vidal-Larramendi, O. Vigil-Galan, CdS and CdTe large area thin films processed by radio-frequency planar-magnetron sputtering. Thin Sol. Film. 403–404, 148–152 (2002)

    Article  Google Scholar 

  2. M.A. Islam, Q. Huda, M.S. Hossain, M.M. Aliyu, M.R. Karim, K. Sopian, N. Amin, High quality 1 μm thick CdTe absorber layers grown by magnetron sputtering for solar cell application. Curr. App. Phys. 13, S115–S121 (2013)

    Article  Google Scholar 

  3. R.S. Mane, C.D. Lokhande, Chemical deposition method for metal chalcogenide thin films. Mater. Chem. Phys. 65, 1–31 (2000)

    Article  Google Scholar 

  4. S. Chander, M.S. Dhaka, Optimization of physical properties of vacuum evaporated CdTe thin films with the application of thermal treatment for solar cells. Mater. Sci. Semicond. Proc. 40, 708–712 (2015)

    Article  Google Scholar 

  5. K. Punitha, R. Sivakumar, C. Sanjeeviraja, V. Ganesan, Influence of post-deposition heat treatment on optical properties derived from UV-Vis of cadmium telluride (CdTe) thin films deposited on amorphous substrate. App. Sur. Sci. 344, 89–100 (2015)

    Article  Google Scholar 

  6. S. Seto, S. Yamada, K. Suzuki, Growth of CdTe on hydrogen-terminated Si(111). J. Crys. Grow. 214–215, 5–8 (2000)

    Article  Google Scholar 

  7. R.K. Sharma, A.C. Rastogi, K. Jain, G. Singh, Microstructural investigations on CdTe thin films electrodeposited using high current pulses. Phys. B 366, 80–88 (2005)

    Article  Google Scholar 

  8. R.H. Williams, M.H. Patterson, Fermi level pinning at metal-CdTe interfaces. App. Phys. Lett. 40, 484 (1982)

    Article  Google Scholar 

  9. D.H. Rose, F.S. Hasoon, R.G. Dhere, D.S. Albin, R.M. Ribelin, X.S. Li, Y. Mahathongdy, T.A. Gessert, P. Sheldon, Fabrication procedures and process sensitivities for CdS/CdTe solar cells. Prog. Photovol. Res. App. 7, 331–340 (1999)

    Article  Google Scholar 

  10. V. Barrioz, G. Kartopu, S.J.C. Irvine, S. Monir, X. Yang, Material utilisation when depositing CdTe layers by inline AP-MOCVD. J. Crys. Grow. 354, 81 (2012)

    Article  Google Scholar 

  11. S. Chander, M.S. Dhaka, Impact of post-deposition thermal annealing on physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cell applications. Physica E 80, 62–68 (2016)

    Article  Google Scholar 

  12. E. Campos-Gonzalez, F. de Moure-Flores, L.E. Ramirez-Velazquez, K. Casallas-Moreno, A. Guillen-Cervantes, J. Santoyo-Salazar, G. Contreras-Puente, O. Zelaya-Angel, Structural and optical properties of CdTe-nanocrystals thin films grown by chemical synthesis. Mater. Sci. Semicond. Proc. 35, 144–148 (2015)

    Article  Google Scholar 

  13. V. Kosyak, A. Opanasyuk, P.M. Bukivskij, YuP Gnatenko, Study of the structural and photoluminescence properties of CdTe polycrystalline films deposited by close-spaced vacuum sublimation. J. Crys. Grwoth 312, 1726–1730 (2010)

    Article  Google Scholar 

  14. A. Abbas, G.D. West, J.W. Bowers, P. Isherwood, P.M. Kaminski, B. Maniscalco, P. Rowley, J.M. Walls, K. Barricklow, W.S. Sampath, K.L. Barth, The effect of cadmium chloride treatment on close-spaced sublimated cadmium telluride thin-film solar cells. IEEE J. Photovol. 3, 1361–1366 (2013)

    Article  Google Scholar 

  15. I. Rimmaudo, A. Salavei, A. Romeo, Effects of activation treatment on the electrical properties of low temperature grown CdTe devices. Thin Sol. Film. 535, 253–256 (2013)

    Article  Google Scholar 

  16. G. Hernandez, X. Mathew, J. Enriquez, B. Morales, M. Lira, J. Toledo, A. Juarez, J. Campos, Structural characterization of CdTe thin films developed on metallic substrates by close spaced sublimation. J. Mater. Sci. 39, 1515–1518 (2004)

    Article  Google Scholar 

  17. S. Chander, M.S. Dhaka, Influence of thickness on physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cell applications. Physica E 76, 52–59 (2015)

    Article  Google Scholar 

  18. M.R. Begam, M.N.M. Rao, S. Kaleemulla, M. Shobana, N.S. Krishna, M. Kuppan, Effect of substrate temperature on structural and optical properties of nanocrystalline CdTe thin films deposited by electron beam evaporation. J. Nano- Electron. Phys. 5, 03019 (2013)

    Google Scholar 

  19. J. Li, J. Chen, R.W. Collins, Optical transition energies as a probe of stress in polycrystalline CdTe thin films. Appl. Phys. Lett. 99, 061905 (2011)

    Article  Google Scholar 

  20. S. Ringel, A. Smith, M. MacDougal, A. Rohatgi, The effects of CdCl2 on the electronic properties of molecular-beam epitaxially grown CdTe/CdS heterojunction solar cells. J. Appl. Phys. 70, 881 (1991)

    Article  Google Scholar 

  21. A. Kabalan, P. Singh, Electrochemical atomic layer deposition and characterization of CdTe and PbTe thin films. J. Nano Res. 31, 30 (2015)

    Article  Google Scholar 

  22. H.I. Salim, V. Patel, A. Abbas, J.M. Walls, I.M. Dharmadasa, Electrodeposition of CdTe thin films using nitrate precursor for applications in solar cells. J. Mater. Sci. Mater. Electron. 26, 3119–3128 (2015)

    Article  Google Scholar 

  23. P. Hu, B. Li, L. Feng, J. Wu, H. Jiang, H. Yang, X. Xiao, Effects of the substrate temperature on the properties of CdTe thin films deposited by pulsed laser deposition. Sur. Coat. Tech. 213, 84–89 (2012)

    Article  Google Scholar 

  24. G. Zoppi, K. Durose, S.J. Irvine, V. Barrioz, Grain and crystal texture properties of absorber layers in MOCVD-grown CdTe/CdS solar cells. Semocond. Sci. Technol. 21, 763–770 (2006)

    Article  Google Scholar 

  25. C. Gaire, S. Rao, M. Riley, L. Chen, A. Goyal, S. Lee, I. Bhat, T.-M. Lu, G.-C. Wang, Epitaxial growth of CdTe thin film on cube-textured Ni by metal-organic chemical vapor deposition. Thin Sol. Film. 520, 1862–1865 (2012)

    Article  Google Scholar 

  26. A. Nakano, S. Ikegami, H. Matsumoto, H. Uda, Y. Komatsu, Long-term reliability of screen printed CdS/CdTe solar-cell modules. Sol. Cell. 17, 233–240 (1986)

    Article  Google Scholar 

  27. X. Li, I.S. Nandhakumar, T. Gabriel, G.S. Attard, M.L. Markham, D.C. Smith, J.J. Baumberg, K. Govender, P.O. Brien, D. Smyth-Boyle, Electrodeposition of mesoporous CdTe films with the aid of citric acid from lyotropic liquid crystalline phases. J. Mater. Chem. 16, 3207–3214 (2006)

    Article  Google Scholar 

  28. B.M. Huang, L.P. Colletti, B.W. Gregory, J.L. Anderson, J.L. Stickney, Preliminary studies of the use of an automated flow-cell electrodeposition system for the formation of CdTe thin films by electrochemical atomic layer epitaxy. J. Elec-trochem. Soc. 142, 3007–3016 (1995)

    Article  Google Scholar 

  29. A.U. Ubale, R.J. Dhokne, P.S. Chikhlikar, V.S. Sangawaran, D.K. Kulkarni, Characterization of nanocrystalline cadmium telluride thin films grown by successive ionic layer adsorption and reaction (SILAR) method. Bull. Mater. Sci. 29, 165–168 (2009)

    Article  Google Scholar 

  30. L.R. Cruz, R. Matson, R.R. de Avillez, Processing of CdTe thin films by the stacked elemental layer method: compound formation and physical properties. Mater. Lett. 47, 63–70 (2001)

    Article  Google Scholar 

  31. H.R. Moutinho, M.M. Al-Jassim, D.H. Levi, P.C. Dippo, L.L. Kazmerski, Effect of CdCl2 treatment on CdTe thin films. J. Vac. Sci. Technol. A 16, 1251–1257 (1998)

    Article  Google Scholar 

  32. L.R. Cruz, L.L. Kazmerski, H.R. Moutinho, F. Hasoon, R.G. Dhere, R. de Avillez, The influence of post-deposition treatment on the physical properties of CdTe films deposited by stacked elemental layer processing. Thin Sol. Film. 350, 44–48 (1999)

    Article  Google Scholar 

  33. J.H. Lee, D.G. Lim, Y.S. Yi, Electrical and optical properties of CdTe films prepared by vacuum evaporation with close spacing between source and substrate. Sol. Energ. Mater. Sol. Cell. 75, 235–242 (2003)

    Article  Google Scholar 

  34. J.P. Enriquez, X. Mathew, XRD study of the grain growth in CdTe films annealed at different temperatures. Sol. Energ. Mater. Sol. Cell. 81, 363–369 (2004)

    Article  Google Scholar 

  35. R. Sathyamoorthy, S.K. Narayandass, D. Mangalaraj, Effect of substrate temperature on the structure and optical properties of CdTe thin film. Sol. Energ. Mater. Sol. Cell. 76, 339–346 (2003)

    Article  Google Scholar 

  36. Y. Bilevych, A. Soshnikov, L. Darchuk, M. Apatskaya, Z. Tsybrii, M. Vuychik, A. Boka, F. Sizov, O. Boelling, B. Sulkio-Cleff, Influence of substrate materials on the properties of CdTe thin films grown by hot-wall epitaxy. J. Crys. Grow. 275, e1177–e1181 (2005)

    Article  Google Scholar 

  37. I.M. Dharmadasa, O.K. Echendu, F. Fauzi, N.A. Abdul-Manaf, H.I. Salim, T. Druffel, R. Dharmadasa, B. Lavery, Effects of CdCl2 treatment on deep levels in CdTe and their implications on thin film solar cells: a comprehensive photoluminescence study. J. Mater. Sci. Mater. Electron. 26, 4571–4583 (2015)

    Article  Google Scholar 

  38. Z. Bai, J. Yang, D. Wang, Thin film CdTe solar cells with an absorber layer thickness in micro- and sub-micrometer scale. Appl. Phys. Lett. 99, 143502 (2011)

    Article  Google Scholar 

  39. S.J. Ikhmayies, R.N. Ahmad-Bitar, Characterization of vacuum evaporated CdTe thin films prepared at ambient temperature. Mater. Sci. Semi. Process. 16, 118–125 (2013)

    Article  Google Scholar 

  40. O. Toma, L. Ion, M. Girtan, S. Antohe, Optical, morphological and electrical studies of thermally vacuum evaporated CdTe thin films for photovoltaic applications. Sol. Energ. 108, 51–60 (2014)

    Article  Google Scholar 

  41. S. Chandramohan, R. Sathyamoorthy, P. Sudhagar, D. Kanjilal, D. Kabiraj, K. Asokan, Optical properties of swift ion beam irradiated CdTe thin films. Thin Sol. Film. 516, 5508–5512 (2008)

    Article  Google Scholar 

  42. J. Toujiskova, J. Kovanda, L. Dobiajisova, V. Pajirizek, P. Kielar, Sputtered indium-tin oxide substrates for CdS/CdTe solar cells. Sol. Energ. Mater. Sol. Cell. 37, 357–365 (1995)

    Article  Google Scholar 

  43. N.H. Kim, C.I. Park, H.Y. Lee, Microstructure, stress and optical properties of CdTe thin films laser-annealed by using an 808-nm diode laser: effect of the laser scanning velocity. J. Korean Phys. Soc. 63, 229–235 (2013)

    Article  Google Scholar 

  44. S. Chander, M.S. Dhaka, Effect of thickness on physical properties of electron beam vacuum evaporated CdZnTe thin films for tandem solar cells. Physica E 84, 112–117 (2016)

    Article  Google Scholar 

  45. A.V. Kokate, M.R. Asabe, P.P. Hankare, B.K. Chougule, Effect of annealing on properties of electrochemically deposited CdTe thin films. J. Phys. Chem. Sol. 68, 53–58 (2007)

    Article  Google Scholar 

  46. E.R. Shaaban, N. Afify, A. El-Tahar, Effect of film thickness on microstructure parameters and optical constants of CdTe thin films. J. Alloy. Comp. 482, 400–404 (2009)

    Article  Google Scholar 

  47. U.P. Khairnar, D.S. Bhavsar, R.U. Vaidya, G.P. Bhavsar, Optical properties of thermally evaporated cadmium telluride thin films. Mater. Chem. Phys. 80, 421–427 (2003)

    Article  Google Scholar 

  48. H.M. Matare, Defect electronics in semiconductors (Wiley-Inter-science, New York, 1971), p. 158

    Google Scholar 

  49. A.A. Al-Ghamdi, S.A. Khan, A. Nagat, M.S.A. El-Sadek, Synthesis and optical characterization of nanocrystalline CdTe thin films. Opt. Laser Tech. 42, 1181–1186 (2010)

    Article  Google Scholar 

  50. R. Swanepoel, Determination of surface roughness and optical constants of inhomogeneous amorphous silicon films. J. Phys. E: Sci. Instrum. 17, 896 (1984)

    Article  Google Scholar 

  51. R. Swanepoel, Determination of the thickness and optical constants of amorphous silicon. J. Phys. E: Sci. Instrum. 16, 1214 (1983)

    Article  Google Scholar 

  52. E.R. Shaaban, I.S. Yahia, N. Afify, G.F. Salem, W. Dobrowolski, Structural and the optical dispersion parameters of nano-CdTe thin film/flexible substrate. Mater. Sci. Semicond. Proc. 19, 107–113 (2014)

    Article  Google Scholar 

  53. E. Marquez, J.M. Gonzalez-Leal, A.M. Bernal-Oliva, R. Jimenez-Garay, T. Wagner, Optical properties of amorphous (As0.33S0.67)100−x Te x (x = 0, 1, 5 and 10) chalcogenide thin films, photodoped step-by-step with silver. J. Non-Crys. Sol. 354, 503 (2008)

    Article  Google Scholar 

  54. A. Purohit, S. Chander, A. Sharma, S.P. Nehra, M.S. Dhaka, Impact of low temperature annealing on structural, optical, electrical and morphological properties of ZnO thin films by RF sputtering for eco-friendly photovoltaic applications. Opt. Mater. 49, 51–58 (2015)

    Article  Google Scholar 

  55. A. Weidlich, A. Wilkie, Anomalous dispersion in predictive rendering. Comput. Graph. Forum 28(4), 1065–1072 (2009)

    Article  Google Scholar 

  56. S. Polosan, A.C. Galca, M. Secu, Band-gap correlations in Bi4Ge3O12 amorphous and glass–ceramic materials. Sol. State Sci. 13, 49–53 (2011)

    Article  Google Scholar 

  57. C. Kittel, Introduction to solid state physics (Wiley, London, 2005)

    Google Scholar 

  58. M.F. Al-Mudhaffer, M.A. Nattiq, M.A. Jaber, Linear optical properties and energy loss function of Novolac: epoxy blend film. Arch. Appl. Sci. Res. 4, 1731–1740 (2012)

    Google Scholar 

  59. K. Punitha, R. Sivakumar, C. Sanjeeviraja, V. Sathe, V. Ganesan, Physical properties of electron beam evaporated CdTe and CdTe: Cu thin films. J. App. Phys. 116, 213502 (2014)

    Article  Google Scholar 

  60. R.D. Gould, C.J. Bowler, D.C. electrical properties of evaporated thin films of CdTe. Thin Sol. Film. 164, 281–287 (1988)

    Article  Google Scholar 

  61. R.W. Birkmire, E. Eser, Polycrystalline thin film solar cells: present status and future potential. Annu. Rev. Mater. Sci. 27, 625–653 (1997)

    Article  Google Scholar 

  62. S. Singh, R. Kumar, K.N. Sood, Structural and electrical studies of thermally evaporated nanostructured CdTe thin films. Thin Sol. Film. 519, 1078–1081 (2010)

    Article  Google Scholar 

  63. S.D. Gunjal, Y.B. Khollam, S.R. Jadkar, T. Shripathi, V.G. Sathe, P.N. Shelke, M.G. Takwale, K.C. Mohite, Spray pyrolysis deposition of p-CdTe films: structural, optical and electrical properties. Sol. Energ. 106, 56–62 (2014)

    Article  Google Scholar 

  64. G.K. Williamson, W.H. Hall, X-ray line broadening from filed aluminium and wolfram. Acta Metall. 1, 22–31 (1953)

    Article  Google Scholar 

  65. H.R. Moutinho, R.G. Dhere, M.M. Al-Jassim, D.H. Levi, L.L. Kazmerski, Investigation of induced recrystallization and stress in close-spaced sublimated and radio-frequency magnetron sputtered CdTe thin films. J. Vac. Sci. Technol. A 17, 1793–1798 (1999)

    Article  Google Scholar 

  66. V. Krishnakumar, J. Han, A. Kelein, W. Jeagermann, CdTe thin film solar cells with reduced CdS film thickness. Thin Sol. Film. 519, 7138 (2011)

    Article  Google Scholar 

  67. V.M. Nikale, S.S. Shinde, A.R. Babar, C.H. Bhosale, K.Y. Rajpure, The n-CdIn2Se4/p-CdTe heterojunction solar cells. Sol. Energ. 85, 1336 (2011)

    Article  Google Scholar 

Download references

Acknowledgments

The authors are highly thankful to the University Grants Commission (UGC), New Delhi for providing financial support under Major Research Project vide F.No.42-828/2013 (SR). The authors are also pleased to acknowledge to Dr. Pawan K. Kulriya, Inter University Acceleration Centre (IUAC), New Delhi and University of Rajasthan, Jaipur for XRD/UV–Vis spectrophotometer and SEM facilities respectively and the Centre for Non-Conventional Energy Resources (CNER), University of Rajasthan, Jaipur for deposition facility. MSD is grateful to the UGC for providing Raman Postdoctoral Fellowship vide F.No.5-1/2013 (IC) for USA. SC is grateful to the Indo-US Science and Technology Forum (IUSSTF), New Delhi for awarding Bhaskara Advanced Solar Energy (BASE) Internship vide file BASE-2016/I/6 to work at USA.

Author information

Authors and Affiliations

  1. Department of Physics, Mohanlal Sukhadia University, Udaipur, 313001, India

    Subhash Chander & M. S. Dhaka

  2. Microelectronics Research Center, Iowa State University of Science and Technology, Ames, IA, 50011, USA

    Subhash Chander & M. S. Dhaka

Authors
  1. Subhash Chander
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. S. Dhaka
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Subhash Chander.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chander, S., Dhaka, M.S. Thermal evolution of physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cells. J Mater Sci: Mater Electron 27, 11961–11973 (2016). https://doi.org/10.1007/s10854-016-5343-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10854-016-5343-2

Keywords

Search

Navigation