Diamond—the ultimate, unrealized semiconductor
The highly unique properties of diamond—including outstanding thermal conductivity and the ability to withstand exceedingly high voltages—make it a formidable semiconductor with a wide range of possible applications, particularly in power electronics. But while these singular properties have long been recognized, diamond has never successfully been used in this way. After extensive research on the subject in the 1980s and 90s encountered more difficulty than success, the attempt to manipulate diamond for use in electronics was essentially abandoned.
Dr. Jesús del Alamo, however, did not lose sight of diamond’s tremendous potential, and recent breakthroughs lead him to believe that further exploration of the subject may yield important results. In order to put diamond to work, a process called surface transfer doping must be employed to transfer electric charge from the surface of the diamond to that of another material. While water and certain organic molecules had been the most popular surface “acceptors,” their high volatility limited the thermal stability of the structures, rendering diamond essentially unusable in application. Dr. del Alamo believes a recent finding in the lab of Rafi Kalish, professor of physics at Technion in Israel, which identified molybdenum trioxide (MoO3) as a successful—and much more stable—acceptor, may hold the key to fabricating functional diamond transistors that could be applied to electronic applications.
Putting diamond back on the table
Working with diamond in this context poses significant challenges. “The diamond surface has very unusual properties,” Dr. del Alamo explains. “Our intuition from conventional semiconductor technology fails. It is unstable and seemingly capricious as we process the material.” To make matters worse, the expense associated with working with diamond can be prohibitive; even for tiny samples that are used and reused to make transistors, the fees are astronomical. Add to these hurdles the fact that after the significant obstacles faced by research teams in the 80s and 90s, research into diamonds as a semiconductor had fallen out of fashion and diamond had become, as Dr. del Alamo puts it, “basically untouchable from a research point of view.”
Dr. del Alamo realized at once that the unique mission of the Bose Research Grants would serve his project well; the Bose Foundation’s commitment to funding difficult-to-fund projects that were both high-risk and potentially high-reward would provide him an opportunity to explore these questions in depth. “That’s what the Bose Fellows Grant has allowed us to do: go after something that’s risky, and let us take the necessary steps to pursue avenues that may lead to significant results, ” he explains. “This is a visionary model.”
The concept of the Bose Grants has unique merit. It fuels the type of research that can generate new fundamental knowledge, fundamental technologies, fundamental contributions to society. I’m confident our work will contribute to this mission.”
Diamond’s unique properties would make it applicable across electronics
Dr. del Alamo says, “While there is a long road ahead, the proposed study could revolutionize the world of power electronics by providing a path to finally exploit the extraordinary electronic and thermal properties of diamond.” Indeed, the possible applications of this technology—which include power electronics, quantum computing, and sensing, as well as biologically compatible electronics—are vast and wide-ranging. “The beauty of the Bose Grant is that we can continue to try different approaches,” he explains. “We’re not positive where we’ll end up, but we are confident we will learn a great deal along the way.”