UC San Diego

With the focus of global energy production shifting towards renewables, efforts have been made to develop sustainable, low-cost technologies to cater to our needs while protecting our environment. The past decade has seen an exponential increase in the popularity of perovskite based solar cells with a push towards commercialization mainly due to its low processing cost, tunability and high efficiency. Despite the attractive advantages offered by perovskite solar cells, one of its shortcomings is its long-term stability. The research community has been invested in tackling issues related to understanding this water-perovskite interaction which poses a threat to device stability. It is known that moisture is one of the most challenging factors to tackle when it comes to degradation of these devices. The presence of water has a detrimental impact on the film’s composition, structure as well as optical properties. Thus, monitoring the uptake of water without destroying the nature of the film altogether is extremely crucial since it directly translates to optimizing the levelized cost of energy efficiency. Researchers have extensively studied the effects of this complex interaction, but there has not been an attempt to isolate the presence of moisture in these films in order to study the cause itself - Water. This thesis aims to study the interaction between water and perovskites using an in-situ and non-destructive technique based on the short-wave infrared (SWIR) spectroscopy.