Engineering360: "Quantum Yields Exceed 100% for Hydrogen Production"

This shows the energy spectrum of insolation, and the tunability of some semiconductors by varying composition.

Somehow these new quantum dots of PbS do not need tuning, since they cover more of the spectrum? 114% Quantum yield of electrons is totally wild.

James, the second graph has the interior labels reversed. Higher photon energies correspond to shorter, ie, bluer, wavelengths.

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The bandgap energy of PbS (and other semiconductor) nanoparticles can be controlled by varying the size of the particles, and so my guess is they're mixing different sizes to cover a wide range of wavelengths. Unfortunately the paper itself is behind a paywall and so I can't confirm this.

That is what I get for finding a sexy (but dead wrong) graphic, and posting it almost without looking. I am having a fit right now. Yes, the right hand graphic is totally mis-labeled - higher energy is to the ultraviolet end of spectrum.

Thanks for additional comments, and still I am shocked we are seeing more than φ=1, even though that does not mean energy is over unity. It is only quantum yield for electrons (pairs) per photon. Still a remarkable accomplishment.