I remember reading something a number of years ago about an idea to make solar cells that were structured in such a way that they would be like an array of tiny antennae to intercept the light in the same way as a radio antenna receives radio waves. Did anything ever come of that idea?
That would be one example of the category of “metamaterials”. The difficulty is that the structures need to be of a size comparable to the wavelength of light, and once you get that small, matter doesn’t behave like you’re used to. Also, there’s a pretty wide variation in wavelength for sunlight, and so you either need antennas tuned to a wide variety of wavelengths, or waste most of the energy that’s in the wrong wavelengths.
What a pile of pretty vaporware! I went looking for estimates on the emissions from launches and found this in the one full report I bothered searching through. And this applies to ALL RISKS:
These risks and issues have been considered qualitatively, given the difficulty in quantifying many of these issues (and the spurious accuracy that would be inherent if such quantifications were attempted).
Which is the whole reason for putting the 1st step of the process in space, where the power can be collected far more efficiently than on the ground. The efficiency of the 1st step allows for inefficiency in the 2nd step.
This reminds me of the idea from a few years back of making solar cells with quantum dots. I think the idea was that there could be a mixture of many different sizes of dots, each size optimized for a different wavelength. So a cell could collect energy from all parts of the spectrum, from UV to IR. I haven’t heard anything about this in quite a while, so apparently it didn’t work out.