Electronic and optical properties of electrochemically polymerized polycarbazole/aluminum Schottky diodes

We report the fabrication of organic Schottky diodes on indium tin oxide (ITO) coated glass by electrochemically polymerized polycarbazole (PCz) with configuration ITO/PCz/Al. The diode has been characterized in respect of electrical and optical properties. The study involves estimation of optical bandgap of the polymer from UV-visible spectroscopic measurements. The current-voltage $(J-V)$ and capacitance-voltage $(C-V)$ characteristics of the Schottky diode were subsequently used for extracting electronic parameters of the device such as ideality factor, barrier height, reverse saturation current, built-in potential, depletion width, doping concentration, etc. The photoresponse of the Schottky contact was measured by illuminating the device with a laser source operating at 650 nm having an incident optical power density of $10mW/cm2$⁠. The device exhibits a high value of peak detectivity $(∼107cmHz1/2W−1)$ near zero bias voltage and the same attains a value of the order of $109cmHz1/2W−1$ at a reverse bias of −6 V.