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Over the past two months three reports from across a range of RASEI collaborations have been released that have focused on improving the stability, efficiency and scalability of perovskite materials for their application in solar cells.

This international, interdisciplinary, highly collaborative community of researchers assembles researchers from across eight different research organizations. The value of approaching a problem from a range of different perspectives highlights the benefits of bringing a diverse team together.

Learn more about this fascinating class of materials and how RASEI researchers are bringing it closer to changing the way we harvest and harness solar energy. 

Science, 2022, 378, 6626, 1295-1300 | Published 12/22/2022

This recent collaborative report, published in Science, brings together researchers from the National Renewable Energy Laboratory (NREL), University of Colorado Boulder (CU Boulder) and the University of Toledo, and includes RASEI Fellows Matthew Beard and Joseph Berry.

Tandem perovskite solar cells hold huge promise for future harvesting of solar energy. This work describes a new approach that greatly improves the reliability and robustness of technologies based on these materials.

Mixed halide perovskites, which contain a mixture of both iodine and bromine, are much more effective at capturing the sun’s energy than perovskites that contain just iodine or bromine. However, when these are repeatedly heated and cooled (as is required if you are going to install these on your roof), the bromine and iodine separate, which significantly reduces the efficiency of these materials. One of the identified causes of this separation is the presence of defects in the perovskite – essentially errors in the way in which the perovskite is stacked.

This report describes a new method that reduces the number of errors in the way the perovskites are built, which helps prevent the iodine and bromine separation, producing much more stable solar cells. Using a technique known as gentle gas quenching allows scientists to create perovskite films with far fewer defects, that have excellent operational stability. Using this new technique the team produced all-perovskite solar cells with 27.1% efficiencies.

ACS Energy Letters, 2022, 7, 12, 4265-4273 | Published 11/02/2022

An international and interdisciplinary team, including RASEI members Seth Marder and Stephen Barlow, report on how the addition a cheap and readily available commodity chemical improves the performance and materials stability of perovskite materials.

This team, that brings together researchers from CU Boulder, the University of Washington, and the University of Oxford (UK), explored another approach to preventing defect formation in perovskites. As perovskite films are constructed, known as crystallization, errors and defects can creep in. The addition of ethylenediamine, an extremely cheap and readily available chemical, modulates the crystallization of the perovskites, which reduces the number of errors in its structure.

Employing the more regular and reliable perovskite structures not only improves the performance and stability of the perovskites in harvesting solar energy, it also provides possibilities for a more reproducible and scalable approach, critical for the application of these materials in real world installations.

ACS Energy Letters, 2023, 8, 898-900 | Published 01/06/2023

Research around perovskite materials has made huge strides in the past decade toward integration into commercial solar cells, but we are not there, yet. This team, which includes RASEI Fellow Mike McGehee, and researchers from the Kaunas University of Technology in Lithuania, and the Helmholtz Zentrum Berlin in Germany, report their work on one of the hurdles that has recently been identified for the reliable manufacture of perovskite-based solar cells.

In the repeated manufacture of perovskite devices in the lab setting it has been observed that the creation of a layer of perovskites has low reproducibility, sometimes it works extremely well, and sometimes the cell is terrible. This report provides evidence that this is due to the nonpolar nature of the surface. In the same way that water on an oily surface doesn’t form a uniform layer and instead forms droplets, the perovskite solution does the same thing.

The team showed that introduction of a polar molecule into the surface made it less ‘greasy’, and the polar perovskite solution made a thin film instead of droplet. This led to the formation of a reliable, reproducible and well covered perovskite solar cells, which showed high energy conversion efficiencies.

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The CHOISE EFRC, led by RASEI Fellow Matt Beard, and including the teams of RASEI Fellows Joe Berry, Joey Luther, Seth Marder, and Mike Toney, was renewed for five years in 2022.

To celebrate this success and convene the team for a brainstorming meeting on developing ideas for this next stage, RASEI worked with the CHOISE team to host a conference in December 2022 at the SEEC Building. This conference brought together over 100 researchers from across the country for three days of presentations, workshops, brainstorming sessions, and poster sessions. 

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Thirteen members of RASEI secured funding from the Department of Energy to participate in inter-disciplinary team science to address a range of challenges associated with combating climate change.

CU Boulder Announcement

In recent decades the scientific endeavor has expanded our knowledge and deepened our understanding of many of the imposing problems that face society. With this improved insight comes an appreciation that many of these issues are multi-faceted, far-reaching, and complex. The climate crisis is the toughest challenge for this generation and is an exceptionally intricate, systematic and multi-layered puzzle. In order to address this challenge in a holistic fashion we need teams of innovative scientists, from across a broad range of scientific and engineering fields, to work together in an inter-disciplinary fashion.

The Renewable and Sustainable Energy Institute (RASEI), a joint institute between CU Boulder and the National Renewable Energy Laboratory (NREL), has prioritized becoming a hub for multi-disciplinary teams focused on climate solutions to work together. Development of this ecosystem anable teams to expand their collaboration across the entire RASEI community, extending to engagement with other academic, national labs and industrial partners along the Front Range. Through fostering a team environment, developing a culture of sharing and integration, RASEI aims to accelerate fundamental discoveries and their translation to applications and solutions that can be deployed to all communities in need.

In August of 2022 the Department of Energy (DOE) released $540 million of funding for research into clean energy technologies and low-carbon manufacturing, $400 million of which is to establish and continue multi-disciplinary team science at Energy Frontier Research Centers (EFRCs). Across the nation 43 EFRCs were funded, with 13 RASEI members involved in six of these Centers.

The EFRC program was established by the DOE Office of Basic Energy Sciences (BES) in 2009 to address the fact that global demand for energy is rapidly expanding, and the way in which energy is collected, stored and used needs to change. The goal of an EFRC is to bring together creative, multi-disciplinary scientific teams to tackle the toughest scientific challenges preventing advances in energy technologies. At the core of an EFRC's mission is to train the next generation of the scientific workforce, both in advanced technical techniques, and also in team science and developing the skills needed to work together to tackle large-scale problems. These Centers are initially funded for four years at about $4 million per year. If the Centers are successful, they can apply for renewed funding at the end of the first four years. Centers can only be renewed once. 

For the 2022 funding announcement, two of the RASEI-infused EFRCs, one of which is based at NREL, were renewals of existing Centers, and the other four awards were to establish new research teams. You can find out more details about the different Centers in the summary boxes below.

The RASEI community is energized to be involved in these exciting collaborative opportunities, and the chance to work together across these teams as part of the RASEI community. Colorado’s U.S. Representative Ed Perlmutter captured this enthusiasm in his quote as part of the funding announcement:

“NREL and CU Boulder, among others, continue to lead our nation in their cutting-edge research and development of a variety of clean energy technologies and low-carbon manufacturing. Their work is essential in the fight to combat climate change and achieve important climate and clean energy goals in the future”

If you would like to keep up with the progress these teams make, check out the  or signup to our monthly newsletter. 

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