Out in the sunlight, the new device is nothing special. It produces a device efficiency of a bit over 11 percent. Given that silicon cells are well above 20-percent efficiencies, this isn't likely to start a mass migration to the technology.
But internally, the device's quantum efficiency seemed quite a bit better, as it was able to extract usable electrons from nearly every photon that was absorbed. The researchers write "the internal quantum efficiency ranges between 90 percent and practically 100 percent," although there are some losses from the connections with the external wiring.
So they decided to give it a test under conditions where those photons were limited: indoor lighting. Even bright indoor lighting is typically only one percent of what you'd get on a sunny day. Unlike the Sun, most lights are also biased toward producing photons in the visible range—which nicely corresponds to the sensitivity of the device's dyes.
Under indoor lighting, the device's efficiency shot up to nearly 29 percent, close to the record for a single-material solar cell. So the researchers tested it against that record holder, gallium arsenide, which is expensive enough that it's normally reserved for uses like space-based solar panels. And the dye-sensitized version won, with gallium arsenide's efficiency dropping to about 20 percent in the dim light.
Soon you may be able to power your basement lab with ambient light.
(Score: 2) by jmorris on Wednesday May 10 2017, @03:58AM
So they say that in a 'brightly lit room' a panel the size of a cell phone (assume a big ass phablet) could generate 30mw. That would power a couple of small but bright white LEDs marketed for outdoor LED panels. (back of the envelope says 30mw could barely power a pair of these [vishay.com] for a total light output of ~1800mcd) They also claim a max of 29% efficient conversion. LEDs also aren't 100% efficient so it would appear energy is being created somewhere in this or the PR spin is a bit out of control.