Director's Message Fall 2018

As highlighted in one of this issue’s InstruMNTL news stories, on the morning of October 26, we will be holding a special ECE-MNTL symposium to recognize the innovation and impact of Professor Nick Holonyak in honor of his 90^th birthday. I especially encourage our graduate and undergraduate students to attend the presentations by several former graduate students from Professor Holonyak’s group, who not only participated in groundbreaking research during their time at Illinois, but who also went on to develop highly successful commercial products and further moved the frontiers of science forward. The impact of Professor Holonyak is literally surrounding us every day through LED illumination and in the semiconductor lasers that make the Internet possible.

I would like to use this opportunity to share my own experience as a graduate student at Illinois, where I was fortunate to take a graduate-level semiconductor physics class taught by Nick, and to be a frequent visitor during his daily coffee talk sessions. Having Nick as a course instructor was an intimidating experience. He would dive deeply into the physics of semiconductors and their associated complex mathematics without referring to notes. His lessons revealed the reasons why we observe fundamental characteristics like band gaps, Fermi levels, photon emission, quantum confinement effects, and all the properties of transistors. The homework problems were nearly impossible by design, and rarely had one correct solution. Much in the way that the identity of the guilty person in a mystery novel is obvious after all the clues are revealed, Nick would bring clarity to highly complex principles, and reveal the beautiful mysteries of semiconductors.

As much as we all loved semiconductor math, our favorite part of the class would be when Nick would stop writing on the chalkboard, lean against the desk, and tell us stories about how the biggest stars in semiconductors—Bardeen, Schockley, Fermi, Hall, Brattain, Esaki—whose names were enshrined in our textbooks as icons, were real human beings with personalities. They struggled to interpret unusual data, pushed their imaginations to develop models that explained their observations, argued passionately with each other, frequently got things wrong, and pushed themselves to make breakthroughs with highly precise experimental lab work.

Nick’s stories revealed that scientists are explorers of the unknown, who feel their way around a problem with a combination of knowledge and intuition, trying to make sense of quantum mechanical processes and arrangements of matter that are too small to observe directly, but whose properties can manifest themselves in observable ways if you are clever enough to construct something that asks the right question. Nick humanized those early pioneers for us, and made us believe that we were currently participating in the same journey of discovery. Nick also showed us that paying close attention to fundamental science principles, being tuned to unexplained anomalies in the data, and taking advantage of a clever trick in the device design or materials of a device, could be used as a powerful lever to gain a fundamental advantage that made all sorts of new things possible. Impurity-induced layer disordering and III-V oxide passivation are just two of the breakthrough methods that come to mind, among many.

When I sought to establish myself in a new career direction in the field of biosensors, I took the lessons that I learned from Nick with me. I can tell that many of Nick’s students have adopted similar approaches. I decided to treat biosensors as a scientific discipline in which fundamental physical processes needed to be understood and leveraged for performance advantages. I sought out novel configurations of materials, fabrication methods, device designs, and applications that could be used to obtain new capabilities that few people thought would be possible.

Much like Nick always pushed to deeply explore the capabilities of heterojunctions, quantum wells, charge carriers, defects, and surfaces, I tried to explore all the aspects of photonic crystals, nanoantennas, nanomaterials, biomolecules, and cells that could push the performance envelope. Rather than following others to jump around from one hot trend to another, I would seek to lead the world in my particular area, laying out a path for others to follow if they wanted to.

When I returned to Illinois as a faculty member in 2004, I was deeply concerned that Nick would think that I “lost the religion” because I no longer worked on compound semiconductors. I recall that I gave a presentation that year about optics-based biosensors that Nick attended, sitting near the front – and I had rarely been so nervous. After my talk, Nick was very complimentary, saying: “now I get what you are doing” and I felt that I had his “OK” to pursue my career in an unusual direction. I am very grateful for all I have learned from Nick, and I hope to pass along many of those lessons to my own students.