NREL - Page 2

Researchers from Northern Illinois University, National Renewable Energy Laboratory (NREL), Northwestern University and Argonne National Laboratory have reported a bilayer back electrode configuration consisting of an Ni-doped natural graphite layer with a fusible Bi-In alloy. This back electrode can be deposited in a vacuum-free approach and enables perovskite solar cells (PSCs) with a power conversion efficiency of 21.0%. These inexpensive materials and facile ambient fabrication techniques can help provide an appealing solution to low-cost PSC industrialization.

A thin layer of gold or silver can help improve the efficiency of perovskite solar cells, but the researchers have found a less expensive material that will enable commercialization of the technology without exorbitant cost.  “A layer of gold in a solar panel or even a layer of silver is probably too expensive,” said Kai Zhu, a senior scientist in the Chemistry and Nanoscience Center at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). “It would make the solar panel not affordable for most people.”

Researchers from the University of Toronto in Canada, Northwestern University, The University of Toledo and University of North Carolina at Chapel Hill in the United States, King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, Yunnan University in China, Ecole Polytechnique Fedérale de Lausanne (EPFL) in Switzerland and University of Warwick in the UK have developed a triple-junction perovskite solar cell with a record efficiency of 24.3% with an open-circuity voltage of 3.21 V. 

The NREL has certified the cell’s quasi-steady-state efficiency as 23.3%, which the team stated is the first reported certified efficiency for perovskite-based triple-junction solar cells. They added that triple-junction perovskite solar cells have so far demonstrated a maximum efficiency of around 20%.

Researchers at the National Renewable Energy Laboratory (NREL), City University of Hong Kong, École Polytechnique Fédérale de Lausanne (EPFL), University of Kentucky, University of Colorado, University of Toledo and Brown University have developed a concept  that simplifies the process of manufacturing perovskite solar cells, which could accelerate their path toward commercialization.

Perovskite solar cells are made by sequentially depositing various layers onto a conductive glass substrate, requiring multiple coatings to create the necessary full device structure. The new technique eliminates or combines some of those steps, thereby simplifying the manufacturing process, which could lead to lower manufacturing costs.

Researchers from NREL, University of Wisconsin—Stout and Swift Solar have reported perovskite-based thermochromic windows that reduce energy load and carbon emission in buildings. The team calculated and fabricated a perovskite-based technology with excellent transition temperatures for building energy savings. 

The use of thermochromic windows in office buildings improves energy efficiency across all climate zones in the United States by modulating the temperature inside, leading to a massive savings, according to the research effort led by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).

Researchers from the US Department of Energy’s National Renewable Energy Laboratory (NREL), University of North Texas and University of Oklahoma have demonstrated that an ultrathin layer of  silicon oxide layer can harden perovskite photovoltaics to protect it from critical stressors in space and on Earth. 

Space has its own unique environmental challenges for solar cells, perovskite ones included. PSCs have to be resilient against such challenges as “radiation, atomic oxygen, vacuum, and high-temperature operation,” according to the study’s abstract.

Researchers at the National Renewable Energy Laboratory (NREL) and University of Toledo have developed a new approach to manufacturing perovskite solar cells.

Developing highly stable and efficient perovskites based on a rich mixture of bromine and iodine is considered critical for the creation of tandem solar cells. However, issues with the two elements separating under solar cell operational conditions, such as light and heat, limit the device voltage and operational stability. This challenge is often made worse by the ready defect formation associated with the rapid crystallization of bromine-rich perovskite chemistry with antisolvent processes.

Researchers at Oxford University, ARC Centre of Excellence for Exciton Science at Monash University,  National Renewable Energy Laboratory (NREL) and SLAC National Accelerator Laboratory have demonstrated a new way to create stable perovskite solar cells, with fewer defects and the potential to rival silicon's durability.

By removing the solvent dimethyl-sulfoxide and introducing dimethylammonium chloride as a crystallization agent, the researchers were able to better control the intermediate phases of the perovskite crystallization process, leading to thin films of greater quality, with reduced defects and enhanced stability.

Researchers at the U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL), in collaboration with scientists from the University of Toledo, the University of Colorado–Boulder, and the University of California–San Diego, have announced a technological breakthrough and constructed a perovskite solar cell with the dual benefits of being both highly efficient and highly stable.

A unique architectural structure enabled the researchers to record a certified stabilized efficiency of 24% under 1-sun illumination, making it the highest reported of its kind. The highly efficient cell also retained 87% of its original efficiency after 2,400 hours of operation at 55 degrees Celsius.

A recent analysis carried out by scientists at the National Renewable Energy Laboratory (NREL) have found that perovskite materials could play an important role in a process to produce hydrogen in a renewable manner.

The NREL scientists analyzed an emerging water-splitting technology called solar thermochemical hydrogen (STCH) production, which can be potentially more energy efficient than producing hydrogen via the commonly used electrolysis method. Electrolysis needs electricity to split water into hydrogen and oxygen. STCH relies on a two-step chemical process in which metal oxides are exposed to temperatures greater than 1,400 degrees Celsius and then re-oxidized with steam at lower temperatures to produce hydrogen.

A collaborative research effort involving scientists from the US National Renewable Energy Laboratory (NREL) and other collaborators, has examined how well perovskite technology might work in the space, such as for powering satellites. The research group has presented guidelines to test the radiation-tolerating properties of perovskites intended for use in space.

'Radiation is not really a concern on Earth, but becomes increasingly intense as we move to higher and higher altitudes,' commented Ahmad Kirmani, a postdoctoral researcher at NREL and lead author of the new study.