This is just a multi-junction photovoltaic cell optimized for temperatures of the radiant body between 1900 and 2400 Celsius degreees.
Such multi-junction photovoltaic cells, but optimized for the higher temperature of the Sun, have existed for many years and efficiencies over 45% are well known.
So there is no point in heating anything, the concentrated solar light must be directed to an appropriate multi-junction photovoltaic cell, for the best efficiency.
Despite their very high efficiency, the multi-junction photovoltaic cells are seldom used for solar energy, because they are expensive, so they can only be used together with light-concentrating mirrors, to achieve a reasonable cost.
Even with mirrors, the price is still much higher than for normal solar panels, so they might be chosen only when space constraints would prohibit the use of a larger area with solar panels.
The exact price is unknown, because you will not find them at retail.
They have been used for solar panels in satellites or space probes, where maximum efficiency is more important than the price, and in experimental solar plants with movable mirrors that concentrate the solar light from a very large area onto a small photovoltaic cell.
In both applications, the complete systems are very expensive and the cost of the photovoltaic cells is a very small part of the total.
Well any area is enough area for solar power, you just don't get much out of it. I think for a car I remember some calculation at some point was that if you covered the whole thing in panels and let it soak in the sun for a day you'd get a few miles of driving out of it.
Having more efficient cells would give you a few more miles I presume. Not too useful for the everyday user, but if you're doing an off grid trip it would be very useful if you camp somewhere and let your car charge for a few days. I guess might as well roll out some proper panels in that case though.
Planes do have a reasonably large wing surface area that could be panelled up if they're not too heavy (you can make quite large RC planes fly perpetually in the sun even with regular monocrystalline panels) so there would definitely be some fuel savings from it if you had like a hydrogen powered jet that already uses electric propulsion.
Such multi-junction photovoltaic cells, but optimized for the higher temperature of the Sun, have existed for many years and efficiencies over 45% are well known.
So there is no point in heating anything, the concentrated solar light must be directed to an appropriate multi-junction photovoltaic cell, for the best efficiency.
Despite their very high efficiency, the multi-junction photovoltaic cells are seldom used for solar energy, because they are expensive, so they can only be used together with light-concentrating mirrors, to achieve a reasonable cost.
Even with mirrors, the price is still much higher than for normal solar panels, so they might be chosen only when space constraints would prohibit the use of a larger area with solar panels.