Japanese physicist Isamu Akasaki, who died April 7 at the age of 92, helped develop blue light-emitting diodes, thus paving the way for LED lights. In 2014, Akasaki won the Nobel Prize in Physics for his achievement, which he shared with Hiroshi Amano of Japan and Shuji Nakamura of the University of California, Santa Barbara.
Learn more about Akasaki in this New York Times article.