Chemist pursues answers to why promising solar cell material quickly degrades

First, product lifetime (aka reliability) is dependent on activation energy of failure modes - chemical or physical reaction processes that degrade the product structure from its functional as-designed form to a non-functional failed form. The higher the activation energy, the longer the "thing" will last at a given temperature or other energy environment.

Second, the activation of failure modes are related to generation/formation activation energies as well - in the case of chemical failure reactions, it's often the exact same activation energy as the formation chemical activation energy. I.e. the activation energy of the chemical reactions used to create the chemical species.

Perovskite PV involve organic molecules - you can't make them nor to they work without these organic chemicals.

And the activation energy of BOTH creating ANY organic molecule and as well as the failure activation energy are ALWAYS lower for organic reactions than equivalent inorganic chemicals especially like silicon and silicon dioxide (silicon PV).

Thus the reliability lifetime of perovskite PV will always be shorter than silicon PV. And this is the reliability physics - you can't change the laws of physics because it's politically correct/desirable.

The very thing that makes organic semiconductors and perovskite PVs "exciting" - low energy to produce them - ALSO is exactly what causes their reliability problems. Activation energy is the barrier to spontaneous chemical or physical reactions and it's either the kT thermal tail and/or QM tunneling that cause both creation and failure reactions to move forward.

Another way to look at "activation energy" is to look at the temperatures at which you manufacture the materials: silicon requires temperatures in the range of 400C-600C but the temperature ranges for organic materials such as those in the perovskite PVs which is closer to 200C-300C.

Thus you use less energy to make them but they are also inherently going to have lower reliability - because physics. So anyone should know this even without knowing much more. This the trivial "back of the envelope" way of predicting that perovskite PV will have worse reliability than silicon PV.

BTW I've been involved in semiconductor reliability for 40 years. This is reliability 101. Chemists generally do not attend the one semiconductor reliability symposium (IEEE IRPS) that deals with this subject so I'm guessing they simply don't know much/enough about reliability to see this. Or they do and they want to goose some funding and papers from the obvious that everyone in the semiconductor industry already knows.