Perovskite solar cells (PSCs) are an emerging solar cell technology showing exceptional efficiency. Real life application and commercialization, however, require devices to remain stable across their 20-to-25-year lifespan. As PSCs are exposed outdoors, multiple stressors inevitably contribute to their degradation. These stressors include humidity, oxygen, bias voltage, varying levels of illumination, and changing temperature.

While the effect of individual stressors on PSCs have been well studied, they do not predict real-life stability. The most common stability test remains aging under maximum power point (MPP) in inert environments. While failure in this test can point to an intrinsic instability of a device architecture or perovskite film composition, success is not a predictor of an actual outdoor lifetime, as acceleration factors are unknown and the effect of encapsulation has not been accounted for.

Ali et al. proposed a more robust set of testing procedures for PSCs, exposing them to more realistic operating conditions to better gauge their real-world performance.

“We hope to move beyond MPP tests to testing encapsulated devices under more demanding accelerated aging protocols, as well as performing more outdoor tests, which are needed to advance PSC stability,” said author Aleksandra Djurišić.

To illustrate the importance of outdoor testing, the authors examined various degradation mechanisms, explored the progress made on outdoor stability testing, and provided guidelines on conducting outdoor tests. They also discussed the effects of intrinsic stability and encapsulation on outdoor stability.

“The PSC community is active in PSC stability research,” said Djurišić. “Round robin outdoor stability tests, similar to those performed on organic solar cells in the past, are highly anticipated to understand effects of different climates on PSC performances.”

Source: “Outdoor stability testing of perovskite solar cells: Necessary step towards real-life applications,” by Muhammad Umair Ali, Hongbo Mo, Yin Li, and Aleksandra B. Djurišić, APL Energy (2023). The article can be accessed at