Re ECF Project: ECF 2015-35

Project Title: Encapsulation of next generation solar cells for high humidity environments

Applicant: Professor Aleksandra Djurisic, Department of Physics, The University of Hong Kong

Total Approved Grant: $499,054 (ECF & WWGF: 50/50)

Duration: 1/4/2016 to 30/9/2017

Project Status/Remarks: Completed

The project aims to develop new encapsulation methods for next generation solar cells containing moisture sensitive active materials (polymer, perovskite) suitable for high humidity environments such as Hong Kong.

Summary of the Findings/Outcomes:
This research investigated the encapsulation of the next generation solar cells (polymer and perovskite solar cells) and found that UV-curable epoxies are preferable for encapsulation of perovskite solar cells, likely due to the damage of the perovskite layer by the outgassing of solvent for thermally curable epoxies. Composite epoxies containing zeolite and reduced graphene oxide (rGO) were prepared and resulted in improvements in the perovskite and/or polymer solar cell lifetimes in the outdoor testing compared to a commercial epoxy. The combination of zeolite-based desiccant and rGO containing composite epoxy resulted in outdoor lifetimes of perovskite solar cells exceeding 1,200 hours during summer months amid adverse weather conditions in Hong Kong (high temperature, high humidity, multiple amber and red rainstorm and typhoon No. 8 warning signals). It achieved enhancement of the lifetime of next generation photovoltaic cells (polymer and/or perovskite) by a factor of 100 compared to devices without encapsulation. Research results exhibited improved performance compared to commercial epoxy, and were published in two journal papers and one conference paper. One public lecture was given in March 2017 and one public seminar was organized in August 2017 at The University of Hong Kong to disseminate the research results.