Moisture and air exposure significantly impact the long-term stability of perovskite solar cells (PSCs). Here’s how these factors affect PSCs:
Moisture Impact
- Degradation Mechanism: Moisture leads to the degradation of perovskite materials by facilitating chemical reactions that break down the structure of the perovskite. This can result in structural changes and the formation of non-perovskite phases, leading to reduced efficiency and stability.
- Hygroscopic Effects: Some components used in PSCs, such as certain hole transport materials, are hygroscopic, meaning they absorb moisture from the air. This absorption exacerbates degradation by introducing additional water molecules into the system.
Air Exposure Impact
- Oxygen Effects: Oxygen exposure is another critical factor affecting the stability of PSCs. Oxygen can accelerate the decomposition of perovskites by promoting oxidation reactions. This results in the release of volatile iodine compounds, contributing to performance degradation.
- Light-Induced Degradation: When perovskites are exposed to both air and UV radiation, they can undergo further decomposition. For instance, the presence of iodine (I2) can form due to UV-induced decomposition, leading to brown discoloration and efficiency loss.
Overcoming Challenges
To mitigate these issues, researchers have explored various strategies, including:
- Protective Coatings: Developing more stable protective layers, such as those based on amidinium, can significantly enhance resistance to moisture and thermal stress.
- Improved Materials: Enhancing the intrinsic stability of perovskite materials and using less hygroscopic components can reduce susceptibility to degradation.
- Encapsulation Techniques: Better encapsulation methods can prevent direct exposure to moisture and air, although thermal stress remains a challenge.
Overall, addressing moisture and air exposure is crucial for improving the long-term stability of perovskite solar cells.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-moisture-and-air-exposure-affect-the-long-term-stability-of-perovskite-solar-cells/
