Rectification and barrier height inhomogeneous in Rhodamine B based organic Schottky diode

Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to study the structure characterization of the Rhodamine B (Rh.B). The thermal stability and the lattice parameters were calculated using TGA and XRD, respectively. Bulk Al/Rh.B Schottky barrier device was prepared and their properties have been investigated by current density–voltage J–V and capacitance–voltage C–V characteristics in the temperature range 300–400 K. The device parameters extracted from the J–V and C–V characteristics are strongly influenced by the effect of temperature. The device exhibits a strong rectification characteristic and shows a maximum rectification ratio at ≈0.15 V for all the studied temperature range. The results clearly demonstrate that the electron transport at the Al/Rh.B interface is significantly affected by low barrier patches. The discrepancy between Schottky barrier heights (SBHs) obtained from the temperature dependencies of both J–V and C–V measurements is explained by the introduction of a spatial distribution of BHs due to the barrier height inhomogeneities that prevail at the Al/Rh.B interface. The deviations of apparent BHs were investigated by considering the microstructure of the Al/Rh.B interface. Moreover, the distribution of carrier concentration through the width of the depletion region is nearly uniform.