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The impact of electrodes and active layer thickness on the current–voltage characteristics of Au/Pentacene/Al structure was studied using a physicallybased 2-D simulation by solving Poisson’s, continuity, and drift diffusion equations. The main parameters required for simulation are extracted from the logarithmic representation of experimental current–voltage curves. The simulation results produce an excellent overlapping with the experimental data after including parameters previously found in our model. Finally, the simulation was used to better understand the physical processes together with mechanisms governing the efficiency of the device under investigation and to have a predictive behavior. [ABSTRACT FROM AUTHOR]

• Planar pentacene Schottky diode fabricated by thermal evaporation technique. • Pentacene films were deposited on n-Si<100> and n-Si<111> substrates. • The pentacene film has uniformly vertically aligned clear boundaries nanograins. • Pentacene Schottky diode performance and Richardson's constant were evaluated. Planar organic Schottky diodes were fabricated using undoped pentacene as an active layer with both palladium and aluminum as contacts. Pentacene organic thin films were deposited on n-type silicon substrates with 100 (n-Si<100>) and 111 (n-Si<111>) orientations. X-ray diffraction (XRD) measurements revealed that the pentacene films' XRD patterns exhibit several peaks with various orientations. The energy-dispersive X-ray technique was used for chemical analysis of the pentacene, and scanning electron microscopy was used to characterize the surface morphology. A structural and morphological study of the deposited pentacene indicates a polycrystalline triclinic (anorthic) nature. A current–voltage curve was experimentally constructed at temperatures (T) ranging from 300 K to 360 K with a step of 15 K. The diode parameters, such as saturation current, ideality factor (n), and barrier height (Φ B), were systematically analyzed using thermionic emission theory. The fabricated devices exhibit decreasing n and increasing Φ B values with increasing T. Richardson's constant for pentacene was calculated, which indicated that the conventionally calculated value from the temperature-dependent characteristic curve is much lower than the calculated theoretical value. It was also observed that the device deposited over the n-Si<111> substrate exhibited larger forward and lower reverse currents than the n-Si<100> substrate device. [ABSTRACT FROM AUTHOR]