Title: The effect of Langmuir arachidic acid layers on surface morphology and electrical properties of a polycrystalline CdS film

Authors: S.A. Klimova; S.V. Stetsyura; S.B. Venig; M. Kaya; I. Dincer; Y. Elerman; A.A. Skaptsov

Addresses: Department of Nano- and Biomedical Technology, Saratov State University, 410012, Saratov, Russia ' Department of Nano- and Biomedical Technology, Saratov State University, 410012, Saratov, Russia ' Department of Nano- and Biomedical Technology, Saratov State University, 410012, Saratov, Russia ' Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler, Ankara, Turkey ' Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler, Ankara, Turkey ' Faculty of Engineering, Department of Engineering Physics, Ankara University, 06100 Besevler, Ankara, Turkey ' Department of Nanotechnology, Nanomechanics, Institute of Nanostructures and Biosystems, Saratov State University, 410012, Saratov, Russia

Abstract: The effect of number of arachidic acid (AA) Langmuir layers and pH values on morphology and local electrical properties of polycrystalline cadmium sulphide (CdS) film was investigated by atomic force microscopy, electric force microscopy (EFM) and scanning Kelvin probe microscopy (SKPM). Atomic force microscopy (AFM) surface analysis showed the polycrystalline relief of CdS surface with the roughness value about 8.5 ± 0.3 nm and the drastic increases up to 25 ± 0.9 nm for semiconductor surface modified by 1, 3 and 5 AA Langmuir layers at both pH value (pH 3.6 and 8.6). Surface potential (SP) values were estimated by EFM method and showed the same sequence of changes and were equal to -1 V for CdS film and to 2.4 V and 3.5 V for 3 AA layers at pH 3.6 and 8.6, respectively. SP of 1 and 5 AA Langmuir layers was about 2 V at both pH values. Furthermore, the electrical characteristics and parameters of samples calculated by EFM quantitative method were compared with SKPM method. EFM analysis showed more pronounced SP value changes than SKPM measuring, due to mathematical value processing of the established Coulomb interaction between the probe and the sample surface.

Keywords: number of Langmuir layers; organic coating of arachidic acid; polycrystalline CdS film; X-ray diffraction; scanning electrostatic force microscopy; Kelvin probe microscopy.

DOI: 10.1504/IJNT.2018.094797

International Journal of Nanotechnology, 2018 Vol.15 No.4/5, pp.402 - 416

Received: 08 May 2021
Accepted: 12 May 2021

Published online: 10 Sep 2018 *

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