Optimizing the thermal annealing temperature: technological route for tuning the photo-detecting property of p-CuO thin films grown by chemical bath deposition method
- 32 Downloads
In the current work, CuO thin films (~ 110 nm) are grown by employing chemical bath deposition (CBD) method on Si substrate for fabricating the p-CuO/n-Si heterojunction photodetectors. The as-grown films are annealed at 250, 550 and 850 °C for 10 min in Ar ambient for tuning optoelectronic properties of the as-grown CuO thin films. Comparative study on systematic annealing of the film within 250–550 °C indicates a morphological change of the as-grown CuO film to nano-fiber type with its chemical composition remaining unchanged. A variation of refractive index and dielectric constant in the range of 2.65–2.93 and 7.2–9.7, and a change of absorption coefficient and bandgap from 1.33 × 105 to 6.06 × 105 cm− 1 and 1.5 to 2.16 eV have been observed. The current–voltage characteristics both in dark and illuminated conditions suggest that the annealing of CuO film at 550 °C provides the best performance in terms of photo-to-dark current ratio and photoresponsivity. A respective enhancement of 5.07 and 10% for the photo-to-dark ratio and photoresponsivity has been observed for the 550 °C annealed sample.
Miss. Jenifar Sultana and Somdatta Paul would like to acknowledge the DST inspire program and University Grants Commission (UGC), India, for providing financial support to pursue their research. The authors would also like to acknowledge the DST Purse program and Center of Excellence (COE), TEQIP for providing infrastructure and financial support to conduct this work.
- 14.D. Wu, Q. Zhang, M. Tao, LSDA+ U study of cupric oxide: electronic structure and native point defects. Phys. Rev. B 73(23), 206–235 (2006)Google Scholar
- 17.E.A. Christie, Spectrally selective blacks for energy collection. International Solar Energy Society Conference (1970), pp. 1–7Google Scholar
- 25.P.K. Nair, M.T.S. Nair, V.M. Garcia, O.L. Arenas, Y. Pena, A. Castillo, I.T. Ayala, O. Gomezdaza, A. Sanchez, J. Campos, H. Hu, R. Suarez, M.E. Rincon, Semiconductor thin films by chemical bath deposition for solar energy related applications. Sol. Energy Mater. Sol. Cells 52, 313–344 (1998)CrossRefGoogle Scholar
- 27.L.F. Koao, B.F. Dejene, H.C. Swart, T.E. Motaung, Dependent of reaction time on Cu-doped ZnO nanostructures prepared by chemical bath method. Int. J. Lumin. Appl. 5, 54–61 (2015)Google Scholar
- 30.S.L. Mammah, F.E. Opara, V.B.O. Pepple, J.E.E. Ntibi, S.C. Ezugwu, F.I. Ezema, Annealing effect on the optical and solid state properties of cupric oxide thin films deposited using the Aqueous Chemical Growth (ACG) method. Nat. Sci. 5, 389–399 (2013)Google Scholar
- 34.Y.L. Liu, L. Liao, J.C. Li, C.X. Pan, From copper nanocrystalline to CuO nanoneedle array: synthesis, growth mechanism, and properties. J. Phys. Chem. 111, 5050–5056 (2007)Google Scholar
- 36.J. Tang, L. Brzozowski, D.A.R. Barkhouse, X.H. Wang, R. Debnath, R. Wolowiec, E. Palmiano, L. Levina, A.G.P. Abraham, D. Jamakosmanovic, E.H. Sargent, Quantum dot photovoltaics in the extreme quantum confinement regime: the surface-chemical origins of exceptional air-and light-stablity. ACS Nano 4, 869–878 (2010)CrossRefGoogle Scholar
- 37.R. Sahay, J. Sundaramurthy, P. Suresh Kumar, V. Thavasi, S.G. Mhaisalkar, and S.Ramakrishna, “Synthesis and characterization of CuO nanofibers and investigation for its suitability as blocking layer in ZnO NPs based dye sensitized solar cell and as photocatalyst in organic dye degradation. J. Solid State Chem. 186, 261–267 (2012)CrossRefGoogle Scholar