J. Dagdelen, K. Zhu, Z. Ma
National Renewable Energy Laboratory,
Keywords: Perovskite solar cells, sol-gel coating, solar cell stability
Summary:Perovskites are a class of crystalline materials with the structure ABX3 that show promise as solar absorber materials. Perovskite solar cells with efficiencies up to 20% can be produced with solution-based processes, making the technology an attractive, inexpensive alternative to silicon. However, the stability of perovskite solar cells is an issue that still needs to be solved. It is believed that perovskite degradation is caused mainly by interaction with atmospheric water vapor. It is hypothesized that hermetically sealing a perovskite-containing device from the atmosphere will increase its stability. This paper introduces an organic/inorganic sol-gel hybrid coating that can extend the life of perovskite films from 10 hours to 3 weeks by providing a barrier to water vapor. Compatibility issues between the sol-gel and spiro-OMeTAD, which is used as a hole transport material that prevents this method from being effective at protecting active devices at this time but further improvement of the hole transport layer can make the coating compatible for the perovskite solar packaging into a module for practical usage.