Study on electrical and photoelectrical behaviour of undoped and doped furazano[3,4-b]piperazine (FP) thin-film devices

Furazano[3,4-b]piperazine (FP), a system where the furazan ring is fused to the saturated heterocyclic ring, was synthesized by oximation of glyoxal, followed by chlorination and then condensation with ethylene diamines to give 2,3-piperazine dione dioxime, which on further cyclodehydration results in the desired furazano piperazine. The material was doped with FeCl3 and CuCl2 in acidic medium. Optical properties were studied in the UV—Vis—IR region. Electrical and photoelectrical properties of Al/FP/ITO, Ag/FP/ITO, Al/Fe-doped FP/ITO and Al/Cu-doped FP/ITO devices were observed. I–V and C–V measurements reveal the formation of the Schottky barrier at Al/FP interfaces. This indicates that FP behaves as a p-type organic semiconductor. J–V characteristics of the Al/FP/ITO device show ohmic conduction in the low voltage region and space charge limited conduction at the high voltage region. Various electrical photovoltaic parameters were calculated from the analysis of I–V and C–V data and are discussed in detail.