Eventually they will stack them like flash memory.

Great! Now mass-produce them, quickly, and sell it for cheap.

I stacked 10 of them for 120% efficiency. It also won't ever come to market.

Lol, they will definitely come to market. Perovskite is getting close to being ready.

I hope you are right. But "getting close to being ready" sounds like you are less than confident.

Not gonna be cheap. These kinds of cells are only really useful for applications where area and / or weight are critical. Why use super complex technology with monocrystalline silicon and a novel semiconductor on top, if you can get 50-60% of the output with a bog-standard polycrystalline cell?

> Why use super complex technology with monocrystalline silicon and a novel semiconductor on top

There is nothing complex about it.

The challenge is finding out if the stuff can last as long as the current alternative.

And if it doesn't last that long, if there are things you can change to make it last longer.

That takes a long time.

That means it's not ready today. If you do some Google though you'll see things are moving a long just fine on that front.

The technology has come a long way over the last decade, we’re probably 3-5 years away from the first commercial installations, residential installations will likely begin a few years after that.