The current transport mechanism of Al/Beetroot/Cu used as an organic semiconductor Schottky diode is superior than natural dye-based thin film devices

The development and characterization of an organic thin-film diode based on herbal dyes has been presented. The electronic parameters of the diode are retrieved using a thermionic emission approach from the I-V characteristics. Furthermore, the computed values of ideality factor (n), barrier height (ϕ) and series resistance (Rs) of Al/Beetroot/Cu using the Cheung and Cheung functions are 4.5, 0.73 eV and 1.10 KΩ, respectively. The values of Rs in these two different approaches are very similar, but a discrepancy in values of n confirms the existence of high Rs and high interface state density. The band gap of betanin and temperature dependence of n, ϕ, and Rs confirm the semiconducting behaviour of beet root. We observed a linear relationship between ϕ and 1/n for Al/Beetroot/Cu, confirming that the device is a Schottky diode. The fact that quantum tunneling plays a significant role in the charge conduction procedure with thermionic emission is confirmed by the parabolic conductance of Al/Beetroot/Cu. We have identified that Schottky emission dominates Poole-Frenkle emission for the Al/Beetroot/Cu diode based on both theoretical and experimental values of β. The G(V) vs V plot was used to explain the existence of the reported dye's trapping effect. We also calculated the device's trap energy (Ec), which is substantially lower than previously reported organic diodes. The theoretically estimated value of the insulating temperature for Al/Beetroot/Cu is 133 K. When we utilise beetroot dye instead of indigo dye, the value of n and Rs decreases from 11.65 to 4.5 and 430 KΩ to 1.1 KΩ, respectively, according to the comparison analysis. The trap energy drops from 0.0732 to 0.021 eV once more. [Display omitted] •The electronic parameters of the diode are retrieved using thermionic emission approach from the I-V characteristics and using Cheung and Cheung function.•Semiconducting behaviour of beet root is confirmed by the band gap and temperature dependence of Rs.•We observed a linear relationship between ϕ and 1/n, for Al/Beet/Cu confirming that the device is a Schottky diode.•The fact that quantum tunneling plays a significant role in the current conduction process with thermionic emission is confirmed by the Parabolic conductance of Al/Beet/Cu.•When we utilise beetroot dye instead of indigo dye, the value of n and Rs decreases from 11.65 to 4.5 and 430 KΩ to 1.1 KΩ, respectively. The trap energy drops from 0.0732 to 0.021 eV once more.