Synthesis, morphology and device characterizations of a new organic semiconductor based on 2,6-diphenylindenofluorene

Issue Title: Special Section: Organic Electronics; Guest Editor: Amlan J. Pal A new organic semiconductor, 2,6-diphenylindenofluorene (DPIF), was synthesized in four steps with a high overall yield of 49.3%. The morphology of thin films of DPIF that were formed under different substrate temperatures was examined by atomic force microscopy and X-ray diffraction analysis. Two different crystalline phases were found to exist depending on the deposition conditions. The DPIF thin film emits around 500-530 nm, while the OLED based on DPIF emits green light with a maximum output over 150 Cd/m^sup 2^ under 35 V. Two typical transistor devices, thin-film transistor (TFT) and semiconductor-metal-semiconductor (SMS) transistor, were fabricated and characterized. DPIF shows a weak n-type character from the TFT device measurement, while SMS transistors using DPIF as an emitter behave like permeable-base transistors with low operating voltages in both common-base and common-emitter modes and a feature of current amplification. Our results demonstrate however, that further research efforts are necessary in order to prevent the observed instabilities. These are quite important, considering that the common-emitter mode is widely used in applications requiring not only switching capability, but also current amplification.[PUBLICATION ABSTRACT]