Brief Bio:
Dr Tawfique Hasan is a University Lecturer in Electronic Materials and Devices at the Cambridge Graphene Centre, Cambridge University Engineering Department. He is also the Deputy Director for Teaching and Training of the Centre for Doctoral Training in Graphene Technology. He gained his PhD in Electrical Engineering from the University of Cambridge in 2009. During his PhD, he worked on carbon nanotube solutions for ultrafast optical pulse generation.
Dr Hasan has held several research positions in the University since his PhD, including a prestigious Royal Academy of Engineering Research Fellowship to work on graphene based flexible and printable devices.
Hasan’s current research focuses on formulation of functional 1- and 2-dimensional nanomaterial inks for a wide range of printable and flexible applications including ultrafast lasers, printable and flexible (opto)electronic, sensing and energy devices such as dye sensitized solar cells, supercapacitors and batteries. Hasan has >70 research articles with ~9000 citations and an h-index of 32.
Abstract：
Solution phase exfoliation allows scalable production of 2 dimensional (2d) materials. Though their dispersions can be used to fabricate printed devices, their sub-optimal fluidic properties present challenges to reliable and uniform material deposition. This is crucial for applications as analog and digital printing could enable large-scale device fabrications based on these materials.
I will present a universal, binder free formulation of functional inks of 2d materials that allows for low temperature curing and reliable inkjet printing on a range of substrates without pre- or post print treatments. Using low surface tension of the constitiuent solvents and difference in evaporation rates, we achieve highly uniform deposition across the printed patterns. We demonstrate this by time-dependent measurement of steadily declining contact angles, suppressing ‘pinning’ of droplet edges and non-uniform deposition. In addition to the fluidic properties, we also determine the optimal print conditions (drop spacing, temperature, line edge variation) to achieve highly uniform and repeatable print patterns at <60 C and demonstrate high (<5%) spatial uniformity through raster scanning. These devices can then be used for various applications, including ultrafast lasers and photodetectors.