Scanning probe investigations of morphology of new p-type material for organic field-effect transistors

Abstract

Organic electronics is a fast growing fi eld of research and technological developments. First applications based on organic electronics have been available on the market for a couple of years, so high resolution colour displays based on organic light-emitting devices are used in digital cameras or mobile phones. Efforts are still going on to find better materials and for a better understanding structure property relationships of organic semiconductors. Although exemplary applications have been realized from polymers and amorphous layers of evaporable molecular materials, crystalline organic semiconductors receive intense attention because the charge-carrier mobilities in these materials are much higher than in polymers or amorphous layers. After optimizing the electronic properties of organic devices (e.g. organic field-effect transistors or organic light emitting diodes) and demonstration of fundamental devices, attention has turned to morphology and composition of the films. Understanding and controlling the morphology of organic films will have a signifi cant impact on the performance of organic-based devices, e.g. by minimizing the number of grain boundaries in the active region of an organic fieldeffect transistor (OFET)