Organic semiconductor interfaces control

The other films were produced to study the influence of the interface between the metal top contact and the organic semiconductor. Here, silicon wafers with a native oxide were used as substrates. The samples were provided by the group of Pflaum at the University of Stuttgart. To minimise impurities, like in the case of DIP, Pc (purchased from Fluka) is purified twice by gradient sublimation before being used as starting material. The films were prepared in UHV at a base pressure of about 7 x 10 mbar from a graphite effusion cell. The evaporation rate was about 3 A/s it was controlled by a quartz microbalance located next to the sample [8]. 

Controlling the chemistry and physics of the dielectric-semiconductor interface is essential to controlling and optimizing the performance of organic electronic devices. There are two main issues associated with the dielectric-semiconductor interface (1) the electrical properties of this interface, which are essential to the reliability, stability, and threshold voltage and (2) the chemical/mechanical properties of the interface, which relate to the ability to orgaiuze the semiconductor layer for efficient charge transport. 

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