Optoelectric response of Schottky photodiode with a PVP: ZnTiO3 nanocomposite as an interfacial layer

Abstract

This work aims to study the photo-response of the fabricated silicon-based Al/PVP:ZnTiO3/p-Si photodiode (PD) in a wide range of illumination intensities. To make a metal-polymer/nanocomposite-semiconductor (MPS) PD, a thin film of PVP:ZnTiO3 nanocomposite is deposited at the interface of the metal-semiconductor (MS) structure. Information regarding the preparation and manufacturing procedures is provided. Through the examination of the current-voltage (I–V) behavior, essential electrical properties such as leakage current (I0), barrier height (ΦB0), ideality factor (n), series and shunt resistances (Rs, Rsh), energy-dependent interface states density (Nss), photocurrent (Iph), and photosensitivity (S) are acquired. The thermionic emission (TE) theory, along with the Norde and Cheung methods, is employed to calculate the parameters ΦB0, n, and Rs. The values of ΦB0 and Rs are decreased by raising the illumination intensity while the n value is increased. In addition, the illumination coefficient (α) and the value of ΦB0 in the ideal case are determined from the ΦB0-P and ΦB0-n plots. The efficiency (η) of the sample is calculated at each illumination intensity whose maximum value is 2.30 % at the intensity of 450 mW/cm2. The illumination-dependent photocurrent is investigated at the negative bias region that shows a good linear behavior in the ln(Iph)-ln(P) profile. The photosensitivity (S) of the fabricated PD is obtained as ⁓500 which is, compared with previous PDs. These findings demonstrate that the developed silicon-based MPS-type PD with a structure of Al/PVP:ZnTiO3/p-Si exhibits a good photo-response and can successfully replace traditional MS PDs in optoelectronic and photovoltaic applications.