I think if you chain LEDs in series, that the power one led makes will be gobbled by the next one in series. Or if you have one led in a chain that isnt getting enough light to breakover, that might be a wall for the electrons to hit. a massive parallel led board might have the best overall gain IMHO?
Also I was thinking about the human hair solar panel, if you use conductive pen that would make it so you don't have to use hot solder.
Interesting! Thanks for bringing this back to my attention!