ECE Professor Umesh Mishra delivers UCSB Faculty Research Lecture: “Thank God for GaN”

December 6th, 2018

umesh mishra presenting at corwin pavilion
In the 63rd annual UCSB Faculty Research Lecture, delivered on November 26, Mishra explained to a large audience why we should, “Thank God for GaN” – the honor is the highest bestowed upon a UCSB professor in recognition of extraordinary scholarly distinction

After being introduced by Chancellor Henry Yang, Mishra spent the next hour explaining why he believes the semiconductor gallium nitride (GaN), which has been the subject of extensive research in the UCSB College of Engineering, is destined to replace silicon as the most important semiconductor material in the world. That would be especially good for UCSB, he added, because “We have pioneered the technologies of these materials.”

He began with recalling that Shuji Nakamura, while working in Japan before becoming a UCSB faculty member, used GaN to invent the blue LED in 1993, which enabled the white LED, which revolutionized lighting around the world and earned Nakamura a Nobel Prize.

“Shuji’s revolution with LED cannot be overstated,” Mishra said. “Efficiency is the best way to minimize the need to produce more power; it is key to a healthy planet. Over forty percent of electricity used now in the U.S. will be saved in 2030 by widespread deployment of LEDs.”

Since the blue LED emerged, GaN has enabled LED and laser lighting applications in consumer electronics, optical switches and circuits, lidar, medicine, space flight, and national defense. When the U.S. Navy needed better radar to identify missiles being launched from mountain caves, UCSB developed GaN-based radar, which was five times more powerful than existing systems. Now, twenty years later, Mishra explained, the Navy is switching its entire radar platform to be based on GaN.

Why does GaN work so well? One reason, Mishra said, is related to defects, known as “dislocations,” which are highly undesirable in most semiconducting materials, because they negatively affect performance. GaN is filled with dislocations, but because they are stable, materials scientists can design around the imperfections.

To have widespread application, Mishra said, “A semiconductor has to be high performance based on where it will be used. It has to be very reliable, and it has to get cheaper with every generation of an application.”

As a case in point, he noted, “LED lights were once twenty dollars each. Now they are about a dollar. The adoption of LEDS is one of fastest technological shifts in human history.

“We are all cost sensitive,” he continued. “People on Amazon don’t go for the highest-cost item. That applies to semiconductors, too. But to get low cost, you have to have wide market penetration. You cannot have only one application and hope for it to be low cost. It has to permeate all the application sets. I believe very strongly that GaN satisfies all these requirements.”

Read the full article from the COE News – “Umesh Mishra’s Faculty Research Lecture: ‘Thank God for GaN’

Related articles:

The UCSB Current – “GaN Rising” – Nov. 15, 2018

The UCSB Current – “The Next Big Challenge” – Apr 16, 2018

Mishra's COE profile