Principal investigator Ashwin Ramasubramaniam of our Mechanical and Industrial Engineering Department leads a joint US-Israel team that has just received a grant from the National Science Foundation’s Division Of Materials Research to promote inexpensive, large-scale fabrication of electronic and optical devices within single sheets of 2D materials. The research promises to make far-reaching impacts on computing, data storage, and consumer electronics.
The co-principal investigators are Todd Emrick of the Department of Polymer Science and Engineering and Michael Barnes of the Chemistry Department at UMass Amherst, in addition to Doron Naveh of the Faculty of Engineering at Bar-Ilan University in Israel.
As the researchers explain in their NSF proposal, two-dimensional (2D) materials are a class of crystalline materials composed of extremely thin sheets (one or a few atoms in thickness) with the potential to create smaller and faster electronic and optical devices. However, since existing methods for preparing such devices are not suited to 2D materials, new approaches must be discovered that promote their easy integration into device constructs.
“This project studies 2D materials that are coated with polymers, which can be applied with extreme precision to manipulate the physical and electronic properties at specific locations,” explain the researchers. “This [method] promotes inexpensive, large-scale fabrication of electronic and optical devices within single sheets of 2D materials, enabling applications in low-power, nanoscale, electronic, and optical devices, including wearable and conformable devices.”
A major challenge in harnessing 2D materials for optoelectronic devices arises from limited avenues for exercising precise control over charge-carrier concentrations, or so-called “doping.” As the researchers say, “This project focuses on Mo and W transition-metal dichalcogenides (TMDCs) with the goal of modulating their optoelectronic properties through novel interfacial chemistries that are more straightforward and robust to implement than direct substitutional doping of the TMDC itself.”
The research team also explains that its integrated theory-synthesis-characterization approach facilitates rational design and application of organochalcogen- and dipole-rich functional polymers for precise, spatially-targeted control over carrier doping, work functions, and band gaps of TMDCs. “This hard-soft, 2D materials platform,” as the proposal explains, “enables the preparation of optoelectronic devices such as photodiodes, transistors, and inverters - key building blocks of digital electronics - fabricated within 2D monolayers using methods that are scalable and compatible with existing semiconductor technology.”
The researchers conclude that “Fundamental advances in the development of polymer-TMDC semiconductors project far-reaching impact on optoelectronic devices, enabling technologies in computing, data storage, and consumer electronics.”
The research program is integrated with formative summer research opportunities for undergraduates from minority-serving institutions, as well as local middle- and high-school students, thereby nurturing the next generation of materials scientists and engineers. Researchers will deliver informal lectures to the broader public in Western Massachusetts to kindle interest in the emerging field of 2D materials. (June 2018)