The perovskite materials used as the basis for highly efficient solar cells are also vulnerable to degradation fromTransmission electron microscope images of the 2D passivation layer. Source: Byungha Shin, KAIST long-term exposure to heat, moisture, oxygen and light. Researchers from Korea Advanced Institute of Science and Technology (KAIST) improved the environmental durability of perovskite by modifying the material with 2D additives to control structural and electrical properties.

The result is a wide bandgap perovskite that retains 80% of its initial power conversion efficiency of 20.7% even after 1,000 hours of continuous illumination. The formation of a 2D layer by inclusion of phenethylammonium enhanced material stability and efficiency. When paired with silicon in a tandem cell design, power conversion efficiency increased to 26.7%.

The researchers hope to use the 1.7 electron volt bandgap perovskite to fabricate a tandem solar cell with a power conversion efficiency exceeding 30%.