Durable Silicon Perovskite Tandem Photovoltaics

Summary

Need

Silicon (Si)-perovskite tandem photovoltaics have shown huge potential in efficiency gains given the rapid increase in performance from 14% (uncertified) in 2015 to 29% (certified) in 2020, surpassing the efficiency record of single junction Si solar cells. While the market is willing to pay a premium for power generated by Si-perovskite tandem with higher efficiency, long lifetime is critical to guarantee the same or lower levelised-cost-of-energy for manufacturers to invest in tandem-cell technology.

Action

This project consists of four work packages:

1. chemical analyses of perovskite and Si-perovskite test structures and cells by gas chromatography in conjunction with mass spectrometry (GC-MS) to identify degradation products and thereby underlying degradation mechanisms
2. spatial luminescence imaging and high-throughput in-situ temporal characterisation of both un-encapsulated and encapsulated perovskite and Si-perovskite test structures and cells to elucidate degradation pathways
3. development of low cost glass-glass bonding encapsulations and electrical feedthroughs compatible with Si-perovskite tandem to eliminate degradation
4. exploration of chemically- or phase-stable perovskite alternatives such as perovskite quantum dots (QD) for Si-perovskite tandem.

Outcome

This project aims to establish measurement protocols for:

1. gas chromatography–mass spectrometry (GC-MS)
2. high-throughput current-voltage measurement and statistical analyses
3. optical-bandgap, luminescent-intensity and absorptivity imaging of perovskites and Si-perovskite tandem cells at different stages of environmental stress.

The project will also increase knowledge of cell degradation mechanisms by identifying:

1. decomposition products and reactions
2. key drivers for electrical performance drop
3. weak spots in cell design and encapsulation.

Finally, the project will establish research capability and capacity to maximise Si-perovskite-tandem durability by developing cell design and encapsulation strategies, such as development of polymer-free glass-glass bonding with hermetic electric feedthrough and the verification phase and optical stabilities of perovskite QD for Si-perovskite-tandem.

Additional impact

This project is expected to create 3.25 full-time equivalent jobs over two years. At least one PhD student will be research trained.