Electrical characteristics and inhomogeneous barrier analysis of aniline green/p-Si heterojunctions

In this study, we identically prepared the aniline green/p-Si organic–inorganic devices (total 27 diodes) formed by direct evaporation of an organic compound solution on to a p-Si semiconductor wafer, and then studied the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of these devices. It was seen that the aniline green organic thin film on the p-Si substrate showed a good rectifying behavior. The barrier heights (BHs) and ideality factors of all devices were extracted from the electrical characteristics. Mean BH and ideality factor were calculated as 0.582 eV and 2.999, respectively from the I–V characteristics. Additionally, the mean barrier height and mean acceptor doping concentration from C–V measurements were calculated as (0.61 ± 0.10) eV and (5.54 ± 0.68) × 10¹⁴ cm⁻³, respectively. The discrepancy in the BH values obtained from I–V and C–V characteristics has been attributed to different nature of the measurements. This can also be due to the existence of the interfacial native oxide and the organic aniline green thin layer between the semiconductor and contacting top metal.