Optical and microelectronic analysis of rhodamine B-based organic Schottky diode: a new trend application

Abstract

The spin-coating technique was effectively used to prepare a good adherent and uniform thin films of rhodamine B (Rh.B). The investigation of the optical absorption revealed indirect energy gap of 2.1 eV and Urbach energy of 29 meV. The investigation of the electrical characteristics of the heterojunction-based Rh.B was achieved to extract the important parameters and identify the predominant conduction mechanism. Dark forward and reverse biasing current density–voltage characteristics showed notable rectification characteristics. The heterojunction conduction mechanism of Rh.B/p-Si confirms that observed mechanisms depend on the applied voltage range. The capacitance–voltage characteristics, measured at different signal frequencies, indicated the occurrence of an abrupt type of heterojunction. The frequency dependence of some heterojunction parameters like barrier height, maximum electric field, the width of the depletion region, and carrier concentration gives an indication for the type of interfacial layer of the heterojunction. A high dependence of the capacitance and conductance on both the biasing voltage and the applied frequency was observed. Moreover, the measured series resistance emphasizes the strong effect on the extracted parameters of the studied Schottky diode. Rh.B-based Schottky diode is a promising for multi-applications in an electronic device.