Analysis of the temperature dependent electrical parameters of the heterojunction obtained with Au nanoparticles decorated perovskite strontium titanate nanocubes

Abstract

Strontium titanate (STO) is one of the important members of the perovskite family and has a wide range of applications in optoelectronics. In this study, the rectifying properties of the heterojunction produced by gold (Au) decorated STO were investigated. Morphological and structural characterization of Au-STO material coated as a thin film, such as SEM, TEM, XRD was performed and the results showed that this structure is a suitable material for heterojunction structures. Current-voltage (I-V) measurements of Ni/Au-STO/n-Si heterojunction devices obtained by coating the Si surface with the spin coating method of Au-STO were performed in the dark and between 60 and 400 K. Additionally, capacitance-voltage (C-V) measurements of the device were made under the same conditions and between 80 and 360 K. Basic diode parameters such as ideality factor (n), barrier height (Фb), series resistance (Rs) were determined from the I-V characteristic of the device using Thermionic emission (TE), Cheung and Norde functions. According to the TE method, the ideality factor of the device was calculated as 1.12 and the barrier height was 0.65 eV at 300 K. The obtained results showed that the Ni/Au-STO/n-Si heterojunction has rectifying properties. In all three calculation methods, as the application temperature increased, the ideality factor of the device decreased and on the other hand, the barrier height increased. This change showed the temperature sensitivity of the Au-STO/n-Si junction.