GOALI: Real Time, Nanoscale Imaging of Electrochemistry and Electroplating in Liquid Media

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

This Grant Opportunity for Academic Liaison with Industry (GOALI) project with the University of Pennsylvania and the IBM T. J. Watson Research Center will study fundamental aspects of electrochemical nucleation, growth, and dendrite formation as functions of substrate and process conditions with a novel imaging tool, the nanoaquarium, which facilitates imaging of electrodeposition in a liquid medium, in real time, with the nanoscale resolution of the transmission electron microscope (TEM). A hermetically-sealed, liquid cell (the nanoaquarium), with a height ranging from tens to hundreds of nanometers, sandwiched between electron-transparent, silicon-nitride windows will be constructed using microfabrication technology for real-time imaging of electrochemical processes with the TEM. The device will be equipped with electrodes for electrochemical plating/dissolution and sensing, and heaters for temperature control. The electrochemical process will be monitored in situ in real time with the electron microscope as a function of solution composition, additives, applied voltage/current, current ramping, electrode geometry, and temperature. The device will enable one to vary process conditions dynamically and monitor and modify parameters in real-time, yielding insights that are inaccessible by other means. The results of the study will assist both in developing basic electrochemical nucleation and growth models and in developing materials systems for various manufacturing processes. UPenn will design and construct the electrochemical nanoaquarium based on a previously successful liquid cell. Collaborative electrochemical experiments and data analysis will then be carried out at both IBM and UPenn. The materials studied will be chosen for their relevance to rechargeable battery technology, thin film photovoltaic cells, and advanced interconnects. Electrochemical processes play a critical role in a plethora of technologies, ranging from energy conversion in batteries, to the production of photovoltaic (PV) cells, to the fabrication of interconnects in high density microelectronics; yet a complete understanding of nucleation, growth, and development of morphology during electroplating is still lacking for many industrially important processes. Since its invention, the electron microscope, with its sub-nanometer resolution has enabled important discoveries in disciplines ranging from materials science to biology. The conventional electron microscope operates, however, in a high vacuum environment and is not capable of imaging processes in liquid media. To enable imaging of processes in liquid media such as electrodeposition and electrodisorption, it is necessary to construct a very thin, hermetically-sealed liquid cell (nanoaquarium) sandwiched between two electron-transparent membranes. Such a device will enable nanoscale observations and a better understanding of the initial, nanoscale stages of the electroplating process that ultimately control the process outcome. In addition to advancing fundamental science, this study will aid the optimization of manufacturing processes, help improve the performance and reliability of rechargeable batteries, and assist in the development of high throughput, low cost production of solar cells and higher density microelectronics. In addition, the nanoaquarium has broad applicability for in situ electron microscope imaging of diverse processes in liquid media such as nano particle self and controlled assembly, formation of metamaterials with unique properties, and biological phenomena. The nanoaquarium is likely to be transformative, provide new insights in diverse disciplines, and enable discoveries. The grant will also facilitate the translation of academic research to an industrial laboratory and enable academic researchers to get acquainted with critical problems encountered by manufacturers. The results of the study, in particular the videos obtained with the nanoaquarium, will be incorporated into instructional material in courses in materials science, electrochemistry, and nanotechnology. In situ electron microscopy videos obtained with the nanoaquarium convey information about dynamical, nanoscale phenomena that is vivid, accessible, and exciting to scientists and non-scientists alike. Narrated videos will be posted on the web for high school students and teachers, undergraduate students, and the public to convey the excitement of discovery and promote interest in science and engineering.