Current voltage perspective of an organic electronic device

Highlights: • V–I characteristics of Au/P3HT/Au has been obtained. • V–I data has been modelled by constructing a cumulative model. • Cumulative model includes physics of charge transport across interface and organic bulk. • The formulated cumulative model has resulted in excellent fit with the experimental data. • Two physical parameters, namely, resistance due to traps and the effective area of cross section, has been worked out. - Abstract: Nonlinearity in current (I) – voltage (V) measurement is a well-known attribute of two-terminal organic device, irrespective of the geometrical or structural arrangement of the device. Most of the existing theories that are developed for interpretation of I–V data, either focus current-voltage relationship of charge injection mechanism across the electrode-organic material interface or charge transport mechanism through the organic active material. On the contrary, both the mechanisms work in tandem charge conduction through the device. The transport mechanism is further complicated by incoherent scattering from scattering centres/charge traps that are located at the electrode-organic material interface and in the bulk of organic material. In the present communication, a collective expression has been formulated that comprises of all the transport mechanisms that are occurring at various locations of a planar organic device. The model has been fitted to experimental I–V data of Au/P3HT/Au device with excellent degree of agreement. Certain physical parameters such as the effective area of cross-section and resistance due to charge traps have been extracted from the fit.