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Large area solution-based inorganic semiconductors and devices for flexible electronics

Professor Manuel Quevedo-Lopez

Professor Manuel Quevedo-Lopez of UT-Dallas will be giving a seminar on flexible electronics on May 24, 1:30 – 2:30 p.m. in W122-D3. Please see below for Professor Quevedo-Lopez’s biography as well as the abstract for his seminar.


Large area solution-based inorganic semiconductors and devices for flexible electronics
M. A. Quevedo-Lopez
Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas, 75080, USA

The field of flexible electronics has expanded tremendously over the past few years. Similar to what happened in silicon integrated circuit technology 40 years ago; flexible electronics are now at a point where system design and process integration will drive the technology. Flexible electronics will likely push the limits of material performance, process integration, circuit design, and system integration to demonstrate the full potential of flexible electronics. In general, key components for any flexible electronic application include thin film transistors. In order to be competitive with state-of-the-art a:Si:H thin film transistors, any other thin film transistor technology must show reproducible transistor parameters such as mobility, threshold voltage, drive current and reliability.

A grand challenge in flexible, thin-film-transistor (TFT) circuitry is the development of complementary metal oxide semiconductor (CMOS) circuits. Although flexible digital circuits, flexible sensors, flexible batteries and solar cells have already been demonstrated, the missing technology piece that must be developed is flexible analog circuitry. For example, an operational amplifier will enable the interface to most sensors and actuators, significantly expanding the functionality of flexible electronic systems. In this talk, we will present n- and p-type chalcogenide-based materials that can be used as the building blocks for analog CMOS-based circuits. In particular, we will introduce the use of chemical bath deposition as an alternative to deposit these materials and will discuss the correlation between device characteristics and materials properties. Photolithography-based chalcogenide-based TFTs processed by chemical bath deposition achieved mobilities in the order of 10-25 cm2/V-s. We also present the impact of semiconductor thickness, gate dielectrics and contact in device performance. In addition, NAND, NOR and Inverters are demonstrated using chalcogenide-based materials integrated with either a-Si or pentacene. Device processing is carried out at a maximum processing temperature of 110oC, which is compatible with most plastic substrates.  Potential application of these materials as radiation sensors is also discussed.

Email: mquevedo [at] (mquevedo[at]utdallas[dot]edu)

Dr. Manuel Quevedo-Lopez is currently an associate Professor in the Department of Materials Science and Engineering at the University of Texas at Dallas. He received his PhD in Materials Science at The University of North Texas (2002).  In 2002 he joined Texas Instruments Silicon Technology Development Group as Member of Technical Staff (MTS). While at Texas Instruments he was appointed SEMATECH assignee from 2004-2006. During his industrial experience, He worked extensively in advanced gate stack materials for Si-based technology. In April 2007 He joined the University of Texas as Dallas as Research Professor and in September 2010 he was appointed Associate Professor at the Materials Science and Engineering Department in the Erik Jonsson School of Engineering and Computer Science. Prof. Quevedo has authored or co-authored over 125 publications in peer reviewed journals, 25 peer reviewed conference proceedings, 10 US patents and given more than 45 invited talks. Dr. Quevedo has also has organized several international meetings.  He is a member of the Materials Research Society, AVS and IEEE. His interests include materials and devices for flexible electronics, flexible non-volatile memory, large area sensors and novel nanostructured semiconductor, dielectrics and contacts for TFT and Energy applications. He currently manages a group of about 16 graduate students and 3 post-docs.