Eli Yablonovitch introduced the idea that strained semiconductor lasers could have superior performance due to reduced valence band (hole) effective mass. With almost every human interaction with the internet, optical telecommunication occurs by strained semiconductor lasers.

He is regarded as a Father of the Photonic BandGap concept, and he coined the term "Photonic Crystal". The geometrical structure of the first experimentally realized Photonic bandgap, is sometimes called “Yablonovite”.

In his photovoltaic research, Yablonovitch introduced the 4(n squared) (“Yablonovitch Limit”) light-trapping factor that is in worldwide use, for almost all commercial solar panels.

His mantra that "a great solar cell also needs to be a great LED”, is the basis of the world record solar cells: single-junction 29.1% efficiency; dual-junction 31.5%; quadruple-junction 38.8% efficiency; all at 1 sun.

His startup company Ethertronics Inc., shipped over 2 billion cellphone antennas.

He co-Founded Luxtera Inc., the originator and world leader of Silicon Photonics, now acquired by Cisco Systems. There is a 2-dimensional Photonic Crystal, in every Luxtera Silicon Photonics chip, millions of which are in major data centers, used by billions all around the globe.

Prof. Yablonovitch is elected as a Member of the National Academy of Engineering, the National Academy of Sciences, the National Academy of Inventors, the American Academy of Arts & Sciences, and is a Foreign Member of the Royal Society of London. He has been awarded the OSA Ives-Quinn Medal, the Benjamin Franklin Medal, the IEEE Edison Medal, the Isaac Newton Medal of the UK Institute of Physics, the Buckley Prize of the American Physical Society, the IEEE W.R. Cherry solar cell award, the Rank Prize (UK), the Harvey Prize (Israel), the IEEE Photonics Award, the IET Mountbatten Medal (UK), the Julius Springer Prize (Germany), the R.W. Wood Prize, the W. Streifer Scientific Achievement Award, and the Adolf Lomb Medal. He also has an honorary Ph.D. from the Royal Institute of Technology, Stockholm, the Hong Kong Univ. of Science & Technology, & McGill Univ., and is honorary Professor at Nanjing University.

Eli Yablonovitch is the Director Emeritus of the NSF Center for Energy Efficient Electronics Science (E³S), a multi-University Center headquartered at Berkeley.

He received his Ph.D. degree in Applied Physics from Harvard University in 1972. He worked for two years at Bell Telephone Laboratories, and then became a professor of Applied Physics at Harvard. In 1979 he joined Exxon to do research on photovoltaic solar energy. Then in 1984, he joined Bell Communications Research, where he was a Distinguished Member of Staff, and also Director of Solid-State Physics Research. In 1992 he joined the University of California, Los Angeles, where he was the Northrop-Grumman Chair Professor of Electrical Engineering. Then in 2007 he became Professor of Electrical Engineering and Computer Sciences at UC Berkeley, where he is the James & Katherine Lau Chair Emeritus in Engineering.