You should really watch that video.
There is some knowledge to be found in there
In short: All panels are coated, to reduce reflection. "Re-usable" reflection is only 2% or so. So the TIPA concept will be less effective than simply covering the same area with plain panels.
However there are other cells under development made from "not Si", which can make use of other wavelengths than Si-based cells. One could create multi-layered cells, that could drive them up to 50%. (Nobody asked about the price of these though - not commercially viable right now, I guess...)
Second is a "solar concentrator" - large array of lenses to concentrate the light on little little cells; running them at 100x the normal intensity of sunlight (or even more) will be more efficient. I didn't know that. Heat is an isse, though. Of course this is a way more komplex construction, and likely more expensive than plain panels.
Well, the "upcoming" technologies have nothing to do with TIPA, which is still BS.