Fabrication of Al / N - BuHHPDI / ITO Schottky Barrier Diode and Investigation of its Electrical Properties

This work explores the electrical characteristics of NButyl-N`-(6-hydroxyhexyl)perylene-3,4,9,10-tetracarboxylic acid diimide (N-BuHHPDI). For this purpose, Al/N-BuHHPDI/ITO Schottky diode is fabricated in which N-BuHHPDI plays the role of an active organic semiconductor layer. A 150 nm thick film of NBuHHPDI is deposited onto an indium tin oxide (ITO) substrate using the vacuum thermal evaporation technique, which allows good adhesion between the N-BuHHPDI and ITO substrate without any significant changes in the electronic characteristics of the thin film. The surface profile of the film is investigated using atomic force microscope (AFM). The current-voltage (I–V) properties of Al/NBuHHPDI/ITO demonstrate clear rectifying behavior with a rectification ratio (RR) of 19.1 at bias voltages of ± 0.25 V which confirms the formation of diode. Under the reverse bias voltage, very minute leakage current is observed. The diode parameters such as ideality factor, series resistance, shunt resistance and barrier height are measured to be 1.61, 1.23 kΩ, 186.29 kΩ and 0.90 eV, respectively. These parameters are also verified by using the Norde’s and Cheung functions. Keywords—N-type organic semiconductor, Perylene, Schottky barrier diode, I-V Characterization