“Surpassing the 17 year record of 12.4 percent, the new efficiency level of 14 percent helps build a promising future for solar hydrogen production” -ECS News
http://www.ecsblog.org/record-breaking-energy-efficiency-levels/
direct link to nature communications paper here:
http://www.nature.com/ncomms/2015/150915/ncomms9286/full/ncomms9286.html#affil-auth
Esposito Research Group Blog 