If you like to get involved in developing new techniques for materials characterization allowing better devices,
while enjoying a pleasant environment for research, training and networking,
you can carry out a PhD in our group:
Development of a new Atomic Force Microscopy technique to characterize polymorphs of thin organic layers and improve OFET performance
The use of semiconducting organic compounds has represented a huge advance in the fabrication of electronic devices. These compounds allow devices to be lighter, more flexible, cheaper and more feasible to manufacture on a large scale than their inorganic counterparts. In an organic field-effect transistor (OFET), the organic compounds in the form of thin films are the active element. The efficiency of the OFET depends on the particular organic molecule, but also its organization within the film. Some semiconducting organic compounds have been found to possess polymorphism (more than one crystal structure). Current laboratory available fabrication processes permit control of polymorphism on a substrate. Recently, the use of liquid-like crystal forms have been proposed as polymorphic precursors to stabilize defect-free thin films in a strategy to enhance the electronic properties of an OFET. The Atomic Force Microscope (AFM) is an ideal tool to determine accurately lattice parameters and crystal orientation of crystalline surface structures. However, its use for molecular resolution is often limited to contact mode methods, which can be invasive and cause thin-film damage. Therefore, the AFM methods for molecular resolution are often restricted to measure solely solid crystal phases.
The proposed PhD project aims to use fabrication processes to generate solid and liquid-like crystal polymorphs of molecular compounds and develop AFM techniques able to detect, with high spatial resolution, the molecular assembly for the thin film phases. AFM sensors with diverse resonance frequencies, spring constants and operating with different eigenmodes and amplitudes will be tested. The full optimization will allow the determination of AFM settings to achieve the highest resolution as a function of the crystal compactness. Once the crystal structures are resolved, OFETs will be fabricated to establish the correlation structure properties.
Eligibility Criteria, How to apply, Evaluation process and Funding conditions