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Applied Physics Seminar

Wednesday, September 13, 2023
4:00pm to 5:00pm
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Noyes 147 (J. Holmes Sturdivant Lecture Hall)
Carbon Negative Technology to Solve the Climate Crisis
Eli Yablonovitch, Professor, Electrical Engineering and Computer Sciences, UC Berkeley,


In 1977, the physicist Freeman Dyson1 proposed the burial of biomass, as a scalable, economical solution to the CO2 problem. Today we know2 that the harvested vegetation should be buried in an engineered dry biolandfill. Plant biomass can be preserved for thousands of years by burial in a dry environment with sufficiently low thermodynamic "Water Activity", which is the relative humidity in equilibrium with the biomass. A "Water Activity" <60% will not support life, suppressing anaerobic organisms, thus preserving the biomass for millenia. Current agriculture costs, and biolandfill costs indicate US$60/tonne of sequestered CO2 which corresponds to $0.53/gallon of gasoline. If scaled to the level of a major crop, existing CO2 can be extracted from the atmosphere and sequester a significant fraction of prior years' CO2 emissions.

  1. F. J. Dyson, "Can we control the carbon dioxide in the atmosphere?" Energy 2, 217-291 (1977).
  2. E. Yablonovitch, & H.W. Deckman, "Scalable, Economical, and Stable Sequestration of Agricultural Fixed Carbon", (Oct. 17, 2022)

More about the Speaker:

Prof. 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.

He was elected to NAE, NAS, NAI, AmAcArSci, and as Foreign Member, UK Royal Society.

For more information, please contact Jennifer Blankenship by email at [email protected].