Space charge limited current–voltage characteristics of organic semiconductor diode fabricated at various gravity conditions

Abstract

In this paper, temperature-dependent current–voltage ( I– V) characteristics of poly- N-epoxipropyl carbazole (PEPC) are evaluated. The PEPC is doped with anthracene (An) and deposited on nickel (Ni) substrate with a centrifugal machine. The films are grown at room temperature but at varying gravity conditions, such as 1 g, 123 g, 277 g and 1107 g, where g is acceleration due to gravity. It is demonstrated that the space charge created by the trapped charges controls the device's characteristics. Thus, by employing trapped space charge limited current model, charge transport parameters are estimated and discussed as a function of ambient temperatures. It is learned that the trap factor, free carrier density, effective mobility and trap density are quasi-linear functions of temperatures. It is shown that devices fabricated at 277 g exhibit superior electrical properties compared to 1 g, 123 g and 1107 g devices. It has been demonstrated that an organic semiconductor device performance could be enhanced by optimizing its fabrication parameters.