CAREER: Scaling Electrolytes to a Single Monolayer for Low-Power Ion-Gated Electronics with Unconventional Characteristics

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

The continuous miniaturization of electronics over the past sixty years has yielded devices that are less power hungry; however, due to physical constraints, the geometric scaling approach is nearing an end. New materials and engineering approaches are needed to push electronics towards lower power and higher information density. One such material is the two-dimensional (2D) semiconductor, a sheet-like material that is only a single molecule thick. Ions - like those used in rechargeable lithium-ion batteries - can be used to control the amount of charge passing through the 2D material to make the operating process more power efficient. This CAREER research reimagines the role of ions in electronics by developing a completely new type of electrolyte to induce charge in the 2D material. Similar to the 2D semiconductor, this electrolyte is also a single molecule thick, and adds new functionalities, such as information storage. The CAREER project explores this new material for application spaces including logic, memory, security and brain-inspired computing. The postdoctoral scholar, graduate and undergraduate students who work on this research benefit from an interdisciplinary project combining soft matter and electronics with the goal of engineering next generation electronics. The research component provides educational examples to be used in the classroom and in outreach efforts to middle and high school students. For example, to inspire curiosity and exploration, a microscope that attaches to the camera of a smart phone will be used by the students to inspect the electrolytes used in this research. While the era of geometric device scaling of high-performance electronics is coming to an end, two-dimensional (2D) materials are being explored for their exciting new physics that can impart novel functionalities in application spaces such as information storage, neuromorphic computing, and hardware security. To develop next-generation electronics based on these materials, charges must be reconfigurable and well controlled. Electric double layer (EDL) gating using ions can provide both ultra-high carrier densities and doping that can be reconfigured between p- and n-type in 2D semiconductors. However, conventional electrolytes are not considered an integral and practical component for future electronic devices because their physical properties (e.g., liquid phase, micron-thick, thermally unstable) are incompatible with the materials and processing of integrated circuits. This CAREER project scales a solid-state electrolyte to the single molecule limit for use in non-volatile, low-power, multi-bit information storage. The intellectual merit comprises materials innovations that include the demonstration of a novel class of electrolyte and the use of this electrolyte to store information. Electrolyte scaling will introduce functionality that can be used by the electronic materials community to explore the fundamental properties of 2D semiconductors and to develop electronics with new device characteristics. The broader impacts are (1) the translation of EDL gating from a measurement tool for exploring transport in 2D crystals to an active device component that enables completely new functionalities, and (2) student training at the intersection of physical chemistry, device physics, and engineering. Outreach activities focused on polymer crystallization will inspire meaningful engagement and independent exploration that increases understanding for middle and high school students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.