The Structural and Electrical Properties of the Au/n-Si (MS) Diodes With Nanocomposites Interlayer (Ag-Doped ZnO/PVP) by Using the Simple Ultrasound-Assisted Method

Abstract

In this paper, Au/Ag-doped ZnO/polyvinyl pyrrolidone (PVP)/n-Si [metal-polymer-semiconductor (MPS)] Schottky Barrier Diodes (SBDs) were fabricated. The structural properties of the Ag-doped ZnO/PVP nanocomposites have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analyses. The XRD pattern indicated that the samples have high purity ZnO and Ag materials and have not observed other peaks. The mean crystallite size of nanoparticles was calculated using Debye-Scherer's equation and the measured sizes reveal clearly the formation of small nanocrystals. The SEM and EDX results show the sheetlike ZnO nanostructures and also confirm the presence of Zn, O, and Ag materials with the nonstoichiometric ratio. The values of ideality factor (n), zero-bias barrier height (Φ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B0</sub> ), and series resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</sub> ) of the MPS-type SBD were obtained from both the thermionic emission (TE) and Cheung function and the observed some discrepancy between them was due to the voltage-dependent of these parameters and the nature of the calculation method. The value of surface states (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ss</sub> ) was changed from 2.2 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> at (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> - 0.44) eV to 8.19 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> eV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> at (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> - 0.69) eV and these values are more suitable for the MPS-type SBD. The values of doping-donor atoms (ND), depletion layer width (WD), and B [capacitance-voltage (C-V)] were obtained from the reverse bias C-2-V plot as a function of frequency. While the value of ND decreases with increasing frequency, WD increases almost as exponentially. However, there is a good relationship between Φ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> (C-V) and ln(f).