Effect of Cu-doped ZnO Thin Films on the Electron–Hole Pair Lifetime in Silicon Wafers

• Published in: SILICON 2023-08, Vol.15 (13), p.5541-5546
• Main Authors: Salem, Moez, Ghannam, Hajar, Salem, Jamel, Moussa, Sana Ben, Massoudi, Imen, Gaidi, Mounir
• Format: Article
• Language: English
• Subjects: Carrier density; Carrier lifetime; Chemistry; Chemistry and Materials Science; Coating effects; Copper; Crystal structure; Environmental Chemistry; Fourier transforms; Inorganic Chemistry; Lasers; Materials Science; Microscopy; Minority carriers; Optical Devices; Optics; Optoelectronics; Passivity; Photonics; Polymer Sciences; Silicon nitride; Silicon substrates; Silicon wafers; Spectrum analysis; Spin coating; Thin films; Zinc oxide; Zinc oxides
• ISSN: 1876-990X; 1876-9918
• DOI: 10.1007/s12633-023-02459-7

In this work, undoped and Cu-doped ZnO thin films were prepared via straightforward co-precipitation and subsequently were applied on silicon substrates using the spin-coating approach. The effect of Cu-doping concentration on the produced films' structural and opto-electronic characteristics was studied. Atomic force microscopy (AFM) and X-ray diffraction (XRD) methods were used to examine the crystal structure and surface morphology of the deposition films. Investigations on surface passivation and reflectivity for Cu-doped and undoped zinc oxide thin films indicates the degree of surface passivation which is assessed using FTIR and photoconductance-based methods. The effective minority carrier lifetime therefore increases from 1.5 to 71 μs at a minority carrier density (n) of 2.10 14  cm −3 . Nevertheless, for λ = 500 nm, the reflectance is reduced from 37% to around 7% once Cu doped ZnO is coated on silicon.