Black-silicon Cell Efficiency above 130 Percent

Dean Sigler Announcements, Solar Power, Sustainable Aviation Leave a Comment

Aalto University in Espoo, Finland has announced a seemingly impossible breakthrough – black-silicon solar cells that exceed 100-percent efficiency.  This breaks the Shockley-Queisser limit, previously thought to be an unbreakable barrier to any solar cell generating more than 33.7-percent efficiency for a single p-n junction photovoltaic cell.  The 1,000 Watts of sunlight falling on a square meter of single-junction solar cells could never produce more than 337 Watts to a battery or other receiving mechanism.  William Shockley, a co-winner of the Nobel Prize in Physics for his co-creation of the transistor and Hans-Joachim Queisser defined this limit at Shockley Semiconductor in 1961. In a traditional solid-state semiconductor such as silicon, a solar cell is made from two doped crystals.  One is an n-type semiconductor, which has extra free electrons, …

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 …