Thickness-dependent phase change and morphological and electric characteristic of devices with pentacene

초록

In this study, pentacene thin films of various thicknesses were fabricated by using the thermal evaporation method, and the phase change, surface morphology and electrical characteristics of these films were analyzed. As the pentacene thin film became thicker, the orthorhombic phase, the thin-film phase, and the bulk phase appeared, in that order, in the measured X-ray diffraction patterns. Also, the roughness was found to change with the phase, as confirmed through atomic force microscopy (AFM). A pentacene-based diode was fabricated, and the threshold voltage and mobility were measured. When the orthorhombic phase was dominant, the diode's threshold voltage and mobility were 3.14 V and 3.64 ×10− 7 cm2/ V·s, respectively, and when the thin-film phase was dominant, those results were 1.50 V and 5.08 × 10− 5 cm2/ V·s. When the bulk phase began to appear, the threshold voltage and mobility of the diode were 2.80 V and 6.75 × 10− 5 cm2/V·s. In this way, we were able to observe the dependenced of the electrical properties on the properties of the phase. © 2019 The Korean Physical Society. All rights reserved.

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