Fresh off revolutionizing TV, quantum dots are making a splash in solar panel news, too, promising to make ultra-efficiency possible by harvesting waste heat, applying a special anti-reflective coating, and even allowing a single electron to hit more than one receptor, essentially creating a pinball machine between the dots, resulting in an overall 114% quantum efficiency from the panels.
NREL scientist Arthur J. Nozik first predicted in a 2001 publication that MEG would be more efficient in semiconductor quantum dots than in bulk semiconductors. Quantum dots are tiny crystals of semiconductor, with sizes in the nanometer (nm) range of 1-20 nm, where 1 nm equals one-billionth of a meter. At this small size, semiconductors exhibit dramatic effects because of quantum physics, such as:
• rapidly increasing bandgap with decreasing quantum dot size,
• formation of correlated electron-hole pairs (called excitons) at room temperature,
• enhanced coupling of electronic particles (electrons and positive holes) through Coulombic forces,
• and enhancement of the MEG process.
Quantum dots confine the charges and harvest excess energy
Quantum dots, by confining charge carriers within their tiny volumes, can harvest excess energy that otherwise would be lost as heat – and therefore greatly increase the efficiency of converting photons into usable free energy.
Not only are these panels ultra-efficient, but they’re much less complicated to manufacture, making them cheaper. All of this brings us one step closer to rolling solar panels off lines and onto houses like we install windows today. Next up for quantum dots is the perfect martini and the cure for the common cold, but they had to save something for 2012.