Cover Picture: Direct Correlation of Organic Semiconductor Film Structure to Field‐Effect Mobility (Adv. Mater. 19/2005)

The use of near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy as a non‐destructive technique to quantify the simultaneous chemical conversion, molecular ordering, and defect formation of soluble oligothiophene precursor films intended for application in organic field‐effect transistors is demonstrated on p. 2340 by DeLongchamp and co‐workers. Illustrated from left to right, with increasing temperature: a) as‐cast, the molecules are weakly oriented; b) at the conversion onset, they become isotropic; c) after full conversion, they are strongly oriented and exhibit maximum field‐effect mobility; and d) overheating reduces film coverage and decreases their orientation, thus lowering their performance.     

Electronic Characterization of Organic Thin Films by Kelvin Probe Force Microscopy

This review highlights the potential of Kelvin probe force microscopy (KPFM) beyond imaging to simultaneously study structural and electronic properties of functional surfaces and interfaces. This is of paramount importance since it is well established that a solid surface possesses different properties than the bulk material. The versatility of the technique allows one to carry out investigations in a non‐invasive way for different environmental conditions and sample types with resolutions of a few nanometers and some millivolts. KPFM can be used to acquire a wide knowledge of the overall electronic and electrical behavior of a sample surface. Moreover, by KPFM it is possible to study complex electronic phenomena in supramolecular engineered systems and devices. The combination of such a methodology with external stimuli, e.g., light irradiation, opens new doors to the exploration of processes occurring in nature or in artificial complex architectures. Therefore, KPFM is an extremely powerful technique that permits the unraveling of electronic (dynamic) properties of materials, enabling the optimization of the design and performance of new devices based on organic‐semiconductor nanoarchitectures.