Advancing Operational Stability of Inverted Perovskite Solar Cells Utilizing Parylene-C Encapsulation Techniques
Elnaz Ghahremani Rad a, Abraha Tadese Gidey a, Towhid Chowdhury a, Alexander R. Uhl a
a Laboratory for Solar Energy and Fuels (LSEF)School of Engineering, The University of British Columbia
Oral, Elnaz Ghahremani Rad, presentation 129
Publication date: 6th February 2024

Following advancements to increase the efficiency of perovskite solar cells, the current emphasis is mainly on enhancing their operational stability. Various methods of encapsulation have been employed to safeguard perovskite solar cells from environmental factors and preserve their efficiency. Recent research studies have primarily focused on using organic/inorganic multilayers to create a more robust barrier against the degradation of perovskite solar cells. [1-3]However, the commercial feasibility of employing inorganic materials might be limited due to their high-cost fabrication process and low flexibility. The encapsulation techniques using polymers stand out for their versatility in material selection and functionality, making them suitable for manufacturing flexible devices. Polymers efficiently act as encapsulants, preventing the infiltration of water and oxygen into the perovskite layer while also inhibiting the release of perovskite composition. One such polymer, parylene-C, offers cost-effective extrinsic protection against environmental harm, mainly humidity and oxygen, to uphold the performance and reliability of perovskite solar cells. [4-5] In our study, we utilized a multilayer deposition of parylene-C with a high light and low water vapor transmission rate, uniformly applied across the surface of the perovskite solar cells. To assess the operational stability of these devices, we employed ISOS-D1 and D2 protocols including conditions such as ambient/ambient and 85ºC/ambient, pertaining to temperature/relative humidity. The obtained results underscore the robustness of inverted control perovskite solar cells coated with parylene-C. These cells reached T80, lasting over 210 hours at an accelerated temperature of 85ºC and 30-35% relative humidity, in contrast to their unencapsulated counterparts, which failed after undergoing the accelerated test for 98 hours. Furthermore, we conducted a study on the operational mechanisms of the devices influenced by degradation using impedance spectroscopy measurements at open-circuit conditions with various irradiances, and dark conditions at different biases.

The authors acknowledge that this work was conducted on the traditional, ancestral, and unceded territory of the Syilx Okanagan Nation (Kelowna). E.G., A.T.G., T.H.C., and A.R.U. acknowledge the financial support provided by the Natural Sciences and Engineering Research Council of Canada (NSERC) through grants RGPIN-2019-05489 and DGECR- 2019-00450 as well as the Canada Foundation for Innovation (CFI) and British Columbia Knowledge Development Fund (BCKDF) through grant 39081.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info