�山����

Russell Everett Hayes

Russell Everett Hayes, a beloved faculty member and professor emeritus in the Department of Electrical, Computer and Energy Engineering (ECEE), died on February 9, 2025. He was 89. A private memorial will be held in early-June.

Hayes joined the �山���� faculty in 1963 after completing his PhD in electrical engineering at Stanford University. Over the course of more than 35 years, he helped shape the department’s graduate program and mentored students and colleagues through his research and teaching. He retired in 1999 and remained connected to the department as an active emeritus professor.

Hayes’ research focused on the physics of semiconductor devices, particularly for microwave, optical and solar energy applications, areas that laid important foundations for both the digital age and the advancement of energy technologies.��

“Russ was often ahead of his time,” said Professor Emeritus Frank Barnes, who hired Hayes in the early-1960s. “I remember talking with him about building 3D semiconductor devices long before industry caught on. He was looking into these problems in the 1990s or earlier, and now, decades later, technologies like these are critical to making artificial intelligence possible.”

Barnes, a former department chair, also described Hayes as instrumental in building the culture and reputation of the department.

“He helped me build the kind of faculty I wanted the department to grow around,” Barnes said. “Russell’s presence helped establish an environment at ECEE that allowed us to recruit top senior faculty and build something special.”

Throughout his career, Hayes published more than 40 research papers and completed prestigious fellowships at institutions such as Cornell University and the Royal Radar Establishment in England. He once described his work as being “on the physics end of electrical engineering.”

“He was right at the frontier of the field,” Barnes recalled. “We went from point-contact transistors to devices on chip and then to integrated circuits. It was a very dynamic time in electrical engineering and Russ was right in the middle of it.”

Barnes also shared a unique story that captured Hayes’ dedication to his students.

“When I was department chair, I received a letter from a student Russ had failed in a course. Instead of complaining, the student thanked him,” Barnes said. “Russ had spent time helping him, working with him and trying to help him understand the material. He didn’t lower his standards, but he genuinely cared. That kind of commitment is rare.”

Hayes was equally admired as a teacher and mentor. He advised numerous graduate students, including now-professor Bart Van Zeghbroeck and former IEEE Microwave Theory and Techniques Society president James Crescenzi. His mentorship had a lasting impact on their careers and on the department as a whole.��

“Russ was my mentor, benefactor and friend,” Van Zeghbroeck said. “He was one of the big influences in my life and a major factor in my leaving IBM and joining CU in 1990. I will never forget him.”

Distinguished Professor Zoya Popovic remembers Hayes as the first person to welcome her to the department when she joined.

“Russell was a wonderful colleague, who was honest and wise with advice,” Popovic said.��

“We had many fun technical conversations related to electromagnetics and semiconductors and Russell was always curious. He loved doing anything outdoors and enjoyed a good glass of wine with friends.”

Distinguished Professor Dragan Maksimovic echoed these sentiments, describing Hayes as “a model scientist, engineer, teacher and colleague and was an exceptional leader who was always willing to listen, offering thoughtful insights and providing constructive guidance.”

Even in retirement, Hayes maintained close ties with former colleagues. His farewell message to the department in 1999 concluded with the simple but powerful line: “Please take care of our department: it is a special place.”

Outside of his academic career, Hayes lived life fully and adventurously. A passionate mountaineer and environmentalist, he was active in the Colorado Mountain Club, serving as president and teaching in the club’s mountaineering school. He also contributed to local conservation efforts as a member of the �山���� County Parks and Open Space Advisory Committee.

Above all, Hayes is remembered not only for his technical contributions, but also for his generosity, integrity and warmth.

As Professor Emeritus Garret Moddel reflected, “Russell was a special person. Those of us who had the privilege to spend time with him will miss him.”