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


La Jolla, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Update

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.

The 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 purpose of this project is to develop robust, high-power perovskite-on-silicon tandem photovoltaic (PV) modules that achieve a power conversion efficiency of greater than 32%, using low-cost manufacturing approaches. The perovskite top cell will be deposited on textured silicon cells, increasing energy production by 30% when the sun is near the horizon, reducing the ramp rate necessary for other grid participants, and improving reliability at future high PV penetrations.

Project Goals

Advance research on tandem solar cells via perovskite-on-silicon tandem (PoSiT) technology.
Improve perovskite solar cell performance and robustness while decreasing the environmental footprint.
Lower the levelized cost of electricity and increase competitiveness of PV emerging technologies.

Project Benefits

Perovskite-on-silicon tandem PV modules seek to achieve a power conversion efficiency of greater than 32% during the project period using low-cost manufacturing approaches that can scale to square meter (m2) products with a projected levelized cost of electricity of $0.031 per kilowatt-hour ($/kWh). These modules will incorporate optimized light-trapping and anti-reflection approaches to collect sunlight at wide angles, increasing energy production in the early morning and late evening to facilitate flattening of the duck curve.

Lower Costs


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 & Public Health

Environmental Sustainability

Perovskite-on-Silicon Tandem (PoSiT) modules could produce 50% higher energy yield per area relative to standard silicon PV.

Key Project Members

Project Member

David Fenning

Associate Professor, NanoEngineering
University of California, San Diego

Match Partners


The Regents of the University of California, on behalf of the San Diego campus


D2Solar LLC


Contact the Team