For the case of perovskite cells, adding layers does not seem to multiply the production cost. Certain uses place a premium on areal efficiency, notably aerosp

For the case of perovskite cells, adding layers does not seem to multiply the production cost. Certain uses place a premium on areal efficiency, notably aerospace. But anybody who has maxed out their own collection area, whether a roof or reservoir, can get more revenue from using better cells. And, the more of that that is done, the faster their price falls. We may reasonably expect the price of multilayer perovskites to drop below cost of silicon panels. Sooner is better, which is driven by maxed-out demand.