Tandem - Page 18

Researchers at the Eindhoven University of Technology have developed a theory that may explain the origins of perovskite solar cells' thermal stability.

The research group's analysis was focused on five types of halide compounds combining both bromide and iodide. 'This combination works particularly well because it allows for the 'tuning' of the bandgap, or the minimum amount of photon energy needed to generate electricity in the material,' they said, adding that this solution is ideal when perovskite PV devices are used in tandem solar cells.

China-based perovskite photovoltaic module developer, UtmoLight, recently launched its new integrated solutions, named Utmorigin that reportedly enable large-area preparation, high efficiency and high stability of perovskite solar cells and include three novel techniques.

During the press conference held for the launch, UtmoLight signed strategic cooperation agreements with partners including SVOLT, an emerging lithium batteries company, FTXT which specializes in hydrogen energy and fuel cell technology, and Greatwall Estate. Together they will explore the application of perovskite solar technology in hydrogen production, energy storage, green construction and more.

Australian researchers from the School of Photovoltaic and Renewable Energy Engineering and the ARC Centre of Excellence in Exciton Science, both based at UNSW in Sydney, have reported that singlet fission and tandem solar cells ' two innovative ways to generate solar power more efficiently ' also help to lower operating temperatures and keep devices running for longer.

Tandem cells can be made from a combination of silicon ' the most commonly used photovoltaics material ' and new compounds like perovskite nanocrystals, which can have a larger bandgap than silicon and help the device to capture more of the solar spectrum for energy generation. Singlet fission is a technique that produces twice the electronic charge carriers than normal for each photon of light that's absorbed. Tetracene is used in these devices to transfer the energy generated by singlet fission into silicon.

Solliance partners TNO, imec/EnergyVille and the Eindhoven University of Technology, have reported a 18.6% efficient highly near infrared transparent perovskite solar cell. When combined in a four terminal tandem configuration with an efficient Panasonic crystalline silicon (c-Si) cell or with a Miasolé flexible CIGS cell, the configuration delivered new record power conversion efficiencies of 28.7% and 27.0%, respectively.

The researchers explained that four terminal tandems allow to build on experience and practices already available in the industry. In addition, four terminal perovskite/c-Si tandems can be applied broadly and are, for example, very beneficial in combination with bifacial c-Si solar cells which, depending on the actual albedo, can readily achieve a total power generation density as high as 320 W/m².

The U.S. Air Force recently awarded the University of Toledo (UToledo) $12.5 million to develop photovoltaic energy sheets that would live in space and harvest solar energy to transmit power wirelessly to Earth-based receivers or to other orbital or aerial instrumentation, such as communications satellites.

UToledo physicists will develop flexible solar cell sheets, each roughly the size of a piece of paper, that can be assembled and interconnected into much larger structures. The team will focus on tandem architectures and work with a variety of combinations of solar cells, perovskites included.

Solliance and U.S-based MiaSolé announced a new record - power conversion efficiency of 26.5% on a tandem solar cell that combined a top rigid semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

This impressive efficiency was achieved by optimizing the bandgap and the efficiency of both the rigid semi-transparent perovskite top cell and the flexible CIGS bottom cell. The CIGS was roll to roll produced on steel foil, with a power conversion efficiency of 20.0%.

A new EU project called "CITYSOLAR" aims to revolutionize the market for transparent solar cells for windows by combining two photovoltaic (PV) technologies in a tandem configuration. The project has received 3,779,242 EUR in support from the H2020 framework programme. Transparent solar cells for windows have been known for several years, but are still not sufficiently efficient - which is what the new project will attempt to change.

'We develop new innovative concepts within light management and solar module integration that are specifically targeted at new promising organic and hybrid thin film PV technologies, and by that we go significantly beyond state-of-the-art in terms of efficiency for transparent photovoltaics. It's a revolutionary new concept,' says Professor Aldo di Carlo, Cnr-Ism, who is coordinator of the new project and is thrilled about the support of "CITYSOLAR" from the H2020 framework.

An international team of scientists, including ones from King Abdullah University of Science & Technology (KAUST) and University of Toronto, set out to increase the performance of solar panels by creating a bifacial (two-sided) tandem solar cell, made of perovskite and silicon materials.

Image credit: U of T

In outdoor environments, light primarily comes directly from the sun. Conventional tandem solar cells can already convert this light into electricity more efficiently compared to traditional silicon-only solar cells by absorbing additional wavelengths of light. Now, the researchers have realized that even more energy can be gathered using a two-sided tandem configuration. Light reflected and scattered from the ground ' referred to as 'albedo' ' can also be collected to significantly increase the current of a tandem solar cell. The new research outlines how the team engineered the perovskite/silicon device to exceed the currently accepted performance limits for the tandem configuration.

Oxford PV has reached a new efficiency world record for perovskite-silicon tandem cells at 29.52%, passing the previous record set less than a year ago by Helmholtz Zentrum Berlin. The new record has been certified by the U.S. National Renewable Energy Laboratory.

The new record was achieved on a cell measuring 1.12cm², produced in a laboratory setting. Oxford PV previously held the tandem cell efficiency record at 27.3%, and then 28%, before a group at Helmholtz Zentrum Berlin (HZB) pushed the record to 29.15% in January 2020. Both Oxford PV and HZB have stated that they have clear roadmaps to push this record beyond 30% in the near future.

U.S -based developer of all-perovskite tandem solar cells, Swift Solar, recently announced that it secured more than $8 million in Series Seed 2 funding, with an additional $1.5 million expected to close soon. Altogether, the company has raised more than $16 million in equity financing to date.

The financing round was led by GitLab CEO Sid Sijbrandij and cryptocurrency player James Fickel. Proceeds will be used to expand R&D, develop prototypes and add staff.