A Wide Band Gap Naphthalene Semiconductor for Thin-Film Transistors

Significance Statement

Organic field transistors attracted considerable attention due to their excellent compatibility with flexible and biological substrates, low cost, easy processing and chemical tunability of properties that enable their wide application in electronics, including: large area flexible displays, smart cards and sensors, biomedical devices and radio frequency identification tags among many more applications. Many high mobility organic semiconductors have been developed based on π-extended acenes, oligothiophene and their derivatives. A majority of organic semiconductors have relatively low band gaps, typically in the visible region of the spectrum (~2-3 eV). On the other hand, large band-gap semiconductors would be beneficial due to their intrinsically higher stability and illumination-independent transport. They could likely find applications in transparent field-effect transistors that are currently fabricated with oxide semiconductors and carbon nanotubes.

Researchers led by professor Dmitrii Perepichka at McGill University in collaboration with professor Hong Meng at Nanjing Tech University in China developed a novel organic semiconductor 2,6-bis(4-methoxyphenyl)naphthalene (BOPNA) with unprecedentedly large band gap of 3.35 eV and an apparent hole mobility measured in thin-film organic field-effect transistors in a saturation regime. Their work, now published in Advanced Electronic Materials, presents a detailed analysis of photo-physical, electrical, and structural properties of BOPNA, showing its high thermal stability, facile morphology reorganization upon annealing at low temperatures, and band-like transport established through the temperature-dependent mobility measurements..

The researchers reported a multi-gram scale high-yield synthesis of BOPNA by a simple Suzuki coupling of commercially available 2,6-dibromonaphthalene with 4-methoxyphenylboronic acid. Photo-physical studies revealed the optical band gap of 372 nm demonstrating complete optical transparency of the film in the visible region. An excellent photo-stability of current response of BOPNA was also observed in the output characteristics of the organic field transistors.

In totality, a novel naphthalene semiconductor BOPNA with a wide band gap of 3.35 eV, high thermal, high photo-stability and complete optical transparency has been synthesized herein. A distinctive characteristic of BOPNA-based transistors is their excellent photo-stability and independence of the electrical characteristics of the illumination conditions; this is important for a wide-range practical application of low-cost organic electronics. Quoting Dr. Perepichka, “it is now clear that a notion of the “semiconducting region” in organic semiconductors being limited by 3 eV band-gap is just a misconception and that it is possible to design efficient field-effect transistors with large band-gap organic materials”.

A Wide Band Gap Naphthalene Semiconductor for Thin-Film Transistors- Advances in Engineering

About The Author

Dr. Lijia Yan is currently a post-doctoral fellow in Southern University of science and Technology. She received PhD in Chemistry from Nanjing Tech University in 2017 and worked in McGill University, Canada as a visiting research scholar for one year. Her PhD project presents a comparative and systematic study of the heteroatom (O, S and C) effects on the charge transport properties of organic semiconductors, in general, and a representative series of new organic semiconductors based on anthracene and naphthalene cores. She has 14 peer-reviewed publications and 15 patents in the field.

About The Author

Filip Popescu obtained his B.Sc. (2013) and M.Sc. (2015) in Chemistry at University of Quebec in Montreal, Canada, where he worked on the Chemical Vapour Deposition synthesis of graphene from vapours of various gas, liquid, and solid hydrocarbon precursors. He is currently a Ph.D. candidate in Chemistry at Mcgill University under the supervision of Prof. Perepichka, studying the structure-property relationships in organic semiconducting molecules and polymers using Organic Field Effect Transistors.

About The Author

Prof. Hong Meng received his PhD from University of California Los Angeles (UCLA) in 2002. He has been working in the field of organic electronics for more than 20 years. His career highlights include work experience in the Institute of Materials Science and Engineering (IMRE), Singapore, and Lucent Technologies at Bell Labs, DuPont Experimental Station. In 2012, Dr. Meng joined the laser printing company and conducted research in the new areas of chemical toner synthesis, special rubber composites and conducting ink formulations. He is also working as an adjunct Professor in the Institute of Advanced Materials, NanjingTech University. In 2014, he joined School of Advanced Materials Peking University Shenzhen Graduate School.

Meng has contributed over 90 peer-reviewed papers (Google Scholar H-Index > 35; citation: 5500), in the fields of chemistry and materials science, filed over 46 US patents, 52 Chinese patents, published several book chapters and co-edited one book titled “Organic Light Emitting Materials and Devices”. He was selected as one of The Recruitment Program of Global Experts (2013).

About The Author

Dmitrii Perepichka is Sir William MacDonald Professor of Chemistry at McGill University. He received PhD in chemistry in 1999 from the Institute of National Academy of Science of Ukraine, followed by post-doctoral training at Durham University with Martin Bryce and at UCLA with Fred Wudl. After his first independent appointment at INRS-Energy, Materials and Telecommunications in Varennes, Canada (2003), he moved to McGill in 2005, where he was tenured in 2010 and promoted to Full Professor in 2014.

The research of his group combines a variety of topics in advanced materials and nanoscience, with a focus on synthesis of novel organic electronic materials, their applications in molecular and thin film devices, and an overarching goal of discovering novel electronic properties. This work has been published in >120 research papers and received the CSC Award for Excellence in Materials Chemistry, Fulbright Research Chair award, DuPont Young Professor Award, among other distinctions.

Reference

Lijia Yan, Filip Popescu, M. Rajeswara Rao, Hong Meng, and Dmitrii F. Perepichka. A Wide Band Gap Naphthalene Semiconductor for Thin-Film Transistors. Advanced Electronic Materials, volume 3 (2017) pages 1-8.

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