Alchemy with Thin Film Structures

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

The blog has looked at several recent attempts to pull electricity from solar cells that have the ability to capture a broad range of light wavelengths.  These are based on everything from layers of graphene and zinc nano-wires, to an exotic subwavelength  plasmonic cavity, to straining solar cells to form wide bandgap funnels which capture light’s energy. Joining these efforts along with those of researchers in America and Germany, colleagues at the Vienna University of Technology are testing single atomic layers of oxide heterostructures, a new class of materials, to “create a new kind of extremely efficient ultra-thin solar cells.” Professor Karsten Held from the Institute for Solid State Physics at the University, explains, “Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own.”  Researchers used large-scale computer simulations to discover that these layered structures “hold great potential for building solar cells.” …

David Birkenstock and Ultimate Efficiency

Dean Sigler Sustainable Aviation Leave a Comment

According to his biography on Airliners.net, “David Birkenstock is a pilot for an east-coast charter and management firm, flying the Turbo Commander 690B and the BeechJet 400A. When he’s not flying, he’s working on modifying a light sport airplane for pressure thrust, hoping to enter it into the NASA Personal Air Vehicle Challenge. He has posted more information about pressure thrust at PressureThrust.com.” Birkenstock’s presentation at the fifth annual Electric Aircraft Symposium in Santa Rosa, California on April 29, 2011 extended his thoughts on pressure thrust, an outgrowth of Fabio Goldschmied’s theories that are well represented in the CAFE Foundation’s library. Most surprising (or maybe not surprising at all) in his talk were comments by major players in the aerospace industry. Around 2000, a senior airflow fellow for a “major airframe manufacturer was quoted as saying, “Our position is that aviation is a mature business and that the discoveries waiting to be identified are probably not worth looking for, much …