Project Name: Approaching the Radiative Efficiency Limit in Perovskite Solar Cells with Scalable Defect Passivation and Selective Contacts
Funding Opportunity: Solar Energy Technologies Office Fiscal Year 2018 Funding Program (SETO FY2018)
SETO Research Area: Photovoltaics
Location: Seattle, WA
SETO Award Amount: $1,250,000
Awardee Cost Share: $300,000
Principal Investigator: David Ginger
-- Award and cost share amounts are subject to change pending negotiations --
This project team will develop thin layers of organic materials to counteract non-radiative defects in perovskite solar cells. Non-radiative defects cause electric-charge carriers, such as mobile electrons, to produce heat, while radiative defects cause these carriers to produce light. When radiative defects produce light, it can be reabsorbed and turned into electricity by the cell, but when non-radiative defects produce heat, the voltage drops, lowering cell efficiency. This team will develop layers of material called passivation layers, which will allow charge carriers to pass through non-radiative defects, allowing the cell to produce higher voltage and achieve higher efficiency.
The team will study passivation layers composed of different organic materials to determine which ones will effectively reduce the losses in voltage and efficiency caused by non-radiative defects in perovskite cells. They will grow thin perovskite films, deposit the selected passivation layers on them, then test how well the passivation layers mitigate non-radiative defects. Using photoluminescence, the researchers will shine a certain amount of light on passivated perovskite solar cells and measure the amount of light re-emitted by the cell from radiative defects. The cells will not be connected to electrical contacts, so that none of the light will be converted into electricity. The goal is 90% re-emission of photons, which would indicate a low number of non-radiative defects.
There is limited knowledge of how to properly passivate defects, but passivation is critical to approaching the open circuit voltage, which is the maximum voltage a solar cell can produce. This team will develop and test passivation layers, determining how to best mitigate these defects. This is a necessary step toward making perovskite solar cells more efficient and longer-lasting.