STM Study Of Perylene Growth On The Ru(0001) Surface With Different Treatments

The electronic devices based on the organic semiconductor such as organic light-emitting diodes,organic photovoltaic cells,and organic field-effect tube,have become a research hotspot in recent years because of their light soft,fast response speed,and other potential advantages.For example,organic light-emitting Devices(OLEDs)have become the dominant direction of display technology with their flexible,low power consumption,low driving voltage and high luminous efficiency advantages.However,Surface adsorption characteristics and growth morphology,from all walks of life to a large extent will affect the charge injection and transportproperties,thus affect the device performance in OLED products.Organic semiconductor devices are usually based on thin film structure,and their outer layers are usually metal electrodes.Therefore organic semiconductor thin film which formed in the epitaxial growth on the metal surface and interface is a very important link.The behaviors of organic semiconductor devices,such as carrier mobility and carrier injection property of metal/organic semiconductor interface,etc.,are strongly dependent on the molecular orientation of organic semiconductor thin film and long-range patterns,what is more,the electronic and optical properties of crystallization thin films are also largely depend on their initial growth orientation andtheir long-range patterns.So understanding the mechanism of the organic semiconductor molecules grown orderly on the metal surface is particularly important.For a given organic semiconductor molecules,the orderly growth in the metal surface are mainly affected by two aspects,one is the interaction between organic molecules;another is the interaction between organic molecule and the substrate.So figuring out the impact of acting force between organic molecule and the substrate on molecular orderly growth,has a very important role in improving the performance of organic semiconductor devices.In this paper we mainly use ultra-high vacuum system of the Scanning tunneling Microscope(STM)to study the adsorption behavior of perylene in the growth on Ru(0001)surface with different treatments at room temperature.Research has shown that for a given organic molecules,the role of the metal substrate can be attributed to provide a suitable template,which can provide the adsorption location for the adsorption of organic molecules.And interactions between organic molecules and substrate determine the degree of this adsorption stability.Under the intermolecular interaction force,organic molecules start to rotate in adsorption position,adjusting the molecular orientation to minimize the interaction force between molecules,eventually reached a suitable molecular orientation.In this way,the cyclical in the distance and coherence on the molecular orientation of organic molecules are shown in the orderly growth on the metal surface.