High-Efficiency Perovskite Tandem Modules with Resilient Interfaces
New perovskite-on-silicon tandem technology benefiting from a new electro-deposition approach.
The Regents of the University of California, on behalf of the San Diego campus
Recipient
La Jolla, CA
Recipient Location
38th
Senate District
77th
Assembly District
$750,411
Amount Spent
Completed
Project Status
Project Result
The team successfully developed perovskite on silicon tandem (PoSiT) cells in a shingled module architecture, moving towards an efficiency of greater than 32% during the project period. The team also were successful in producing a mechanically-compliant conductive adhesive (MCCA) to dramatically reduce or eliminate the silver content, a depositional process for the MCCA, and all layers necessary for the perovskite top cell atop silicon cells produced on a real manufacturing line.
View Final ReportThe Issue
The dominant commercialized silicon (Si) PV technology has plateaued at 18-24% conversion efficiency, and the theoretical limit for any single-absorber solar cell under standard operating conditions (1 sun, 25 degrees C) is approximately 30.5%. While other absorbers, such as perovskites, have attracted significant attention in recent years for offering a high quality semiconductor, with lower purity and lower fabrication temperatures than silicon (Si), the price of Si modules has fallen by 45% in the last three years to $0.36 per watt ($/W), leaving minimal margin or market for emerging single-absorber PV technology that can only achieve similar efficiency.
Project Innovation
The team successfully developed PoSiT cells and a shingled module architecture using silver-free conductive adhesives, moving the technology toward a realizable efficiency of greater than 32 percent. Using the custom-built automated perovskite solar cell assembly line robot, the project team optimized material properties, such as what light is absorbed and the stability of the material against degradation under high temperatures. These experiments were complemented by simulations to optimize perovskite solar cell design. The perovskite materials were deposited using solution coating methods atop commercially available silicon solar cells. The project team demonstrated the viability of this solution-processing technique to deposit high quality perovskite films on the rough surfaces of commercial silicon solar cells.
Project Goals
Project Benefits
This project explored the use of multiple materials in a solar cell to absorb the sunlight, each capturing different parts of the solar spectrum, to push the efficiency boundaries beyond the current plateau. The project team’s goal was to create innovative solar cells with two light-absorbing layers that can achieve a power conversion efficiency of 32 percent and levelized cost of electricity of $0.031 per kilowatt-hour. These new modules, when commercialized, are expected to reduce electricity costs to California ratepayers and investor-owned utilities by boosting PV module power and energy over time, particularly in space-constrained distributed generation scenarios such as rooftop installations.
Affordability
The project moved Perovskite-on-Silicon Tandem (PoSiT) module technology further on the path to a levelized cost of electricity (LCOE) 30% lower than traditional silicon PV when manufactured at scale, which will result in lower costs to ratepayers.
Environmental Sustainability
Perovskite-on-Silicon Tandem (PoSiT) modules could produce 50% higher energy yield per area relative to standard silicon PV.
Key Project Members
David Fenning
Subrecipients
D2 Solar
Match Partners
The Regents of the University of California, on behalf of the San Diego campus
D2 Solar
