What is the limitation of cells made only with perovskite?

• A. They degrade within days.
• B. They require rare earth metals.
• C. They are no more efficient than silicon-based ones.
• D. They cannot operate above 50°C.

Answer: (C)

Perovskite solar cells face their biggest challenge in stability over time. The material is highly sensitive to moisture, oxygen, heat, and light, which can cause chemical changes, phase transitions, or ion migration that degrade performance. This means a device can lose efficiency or fail if it isn’t well protected by robust encapsulation and stable compositions. Despite that drawback, perovskites have demonstrated high efficiencies competitive with silicon, so the limitation isn’t an inherent ceiling on performance but how well the cells hold up under real-world conditions. The other statements don’t capture the main issue: they don’t inherently require rare earth metals, they can operate at temperatures above modest limits with proper engineering, and the practical concern isn’t that their efficiency can’t exceed silicon’s.