Statistical analysis of characteristic parameters of graphene/p-Si junctions prepared under similar conditions

Abstract

The literature has established that the junction parameters in metal-semiconductor rectifying junctions closely depend on the smoothness of the semiconductor surface and the properties of the materials used in contact construction. In addition to metals, materials with excellent properties such as graphene are utilized as contact materials in the fabrication of metal-semiconductor rectifier junctions, which are the fundamental part of many innovative devices, particularly diodes. Ten Au/graphene/p-Si/Al complex structures were created in this study using comparable circumstances. Using the plasma enhanced chemical vapour deposition (PECVD) method, graphene thin film was initially produced on copper foil and subsequently transferred on the clean and polished surface of p-Si semiconductor with aluminum ohmic contact. Electrical measurements such as current-voltage (I–V) and capacitance-voltage (C–V) of the fabricated 10 graphene/p-Si junctions were performed at room temperature and in the dark. Some characteristic parameters such as threshold voltage, ideality factor, barrier height, leakage current and rectification ratio were calculated. The barrier heights from the I–V characteristics varied from 0,532 to 0,736 eV, the ideality factors varied from 2,028 to 2,302, and from the C–V characteristics the barrier heights varied from 0,743 to 0,793 eV at 300 kHz. After fitting a Gaussian function to the barrier height distributions derived from the I–V and C–V characteristics, the mean barrier height values were found to be 0,610 eV and 0,772 eV (at 300 kHz), respectively. The value of the lateral homogeneous barrier height for the ten graphene/p-Si junctions prepared was determined to be 0,652 eV based on the linear relationship between the barrier height and the ideality factor values.