A research team at the Fraunhofer Institute for Solar Energy Systems ISE has reported a perovskite/perovskite/silicon triple-junction solar cell with an open circuit voltage of >2.8 V, which is said to be the record value reported for this structure so far. The Fraunhofer team showed that perovskite-perovskite-silicon subcells can hold considerable promise and have an even greater efficiency potential than double-junction tandem cells.

The triple-junction solar cell was developed as part of the Triumph research project funded by the European Commission and the RIESEN research project funded by the German Federal Ministry for Economic Affairs and Climate Action. This achievement confirms that the cell has excellent material properties for generating electricity, leading the scientists to deduce that it has an efficient solar cell architecture.

Researchers from Princeton University and the King Abdullah University of Science and Technology (KAUST) have connected silicon solar cells with perovskite ones in a tandem solar cell to not only boost overall efficiency, but also to strengthen stability. The results show that the connection protects the frail perovskite solar cell from voltage-induced breakdown while attaining greater efficiencies than either cell can achieve on its own.

The team demonstrated that the tested perovskite/silicon tandem devices are considerably more resilient against reverse bias compared with perovskite single-junction devices. The origin of such improved stability stems from the low reverse-bias diode current of the silicon subcell. This translates to dropping most of the voltage over the silicon subcell, where such a favorable voltage distribution protects the perovskite subcell from reverse-bias-induced degradation.

Solaires Entreprises Inc. is a Canadian solar energy startup based in Victoria, BC., who has developed perovskite materials and photovoltaic (PV) modules, designed for integration into IoT devices, small consumer electronics, and smart gadgets. Powered by indoor light, the cells are extremely efficient, modular, and are configurable to suit the application.

Dr. Sahar Sam is Solaires Chief Science Officer, and she was kind enough to answer a few questions we had about Soliares. Dr. Sam holds a B.Sc. and an M.Sc. in Materials Science and Engineering from Shiraz University and a Ph.D. in Mechanical Engineering from the University of Victoria. 

Hello Dr. Sam! We'll be happy to get a short introduction to Solaires, the technology, and products.

Founded in 2020 in Victoria, BC, Solaires Entreprises Inc is at the forefront of the next generation of photovoltaics, targeted for both outdoor light and indoor light, by harnessing the promise of perovskites. Our perovskite photovoltaics are light, thin and made of readily available and low cost materials.

South Korea’s automotive giant, Hyundai Motor Group, recently unveiled several new nanotechnologies for future mobility at the Nano Tech Day 2023 event in Seoul. 

Besides inventions like a “self-healing polymer coating” that enables the car to repair its own scratches, perovskite/silicon tandem solar cells were also introduced. It was said that Hyundai Motor Group believes that by applying tandem solar cells to areas that receive direct sunlight, such as the engine compartment cover, top panel, and doors of eco-friendly vehicles, it will be possible to generate enough electricity for daily driving.

In two separate studies, researchers report novel methods that enable the fabrication of high-performance perovskite-silicon tandem solar cells with power conversion efficiencies exceeding 30%. 

Combining perovskite and silicon solar cells into a tandem device could provide a promising path toward high-performance PVs. Here, in the two separate studies, researchers present different strategies for developing perovskite-silicon tandem solar cells with a PCE exceeding 30%. In one study, Xin Yu Chin from Ecole Polytechnique Fédérale de Lausanne (EPFL) and colleagues showed that the uniform deposition of the perovskite top cell on a silicon bottom cell featuring micrometric pyramids – the industry standard configuration – can facilitate high photocurrents in tandem solar cells.

The following is a sponsored post by MBRAUN

Germany-based inert gas leading solutions provider MBRAUN is offering a wide range of solutions for the perovskite industry, ranging from R&D systems to full-industrial solutions. One of the company’s customers, KAUST University in Saudi Arabia, recently announced a word record with the help of MBRAUN systems.

Erkan Aydin, Professor and Researcher Scientist at KAUST, says: “In two months' time, we've set a new world record for perovskite/silicon tandem solar cells - again! With our latest update, perovskite/silicon tandem solar cells have reached impressive 33.7% certified power conversion efficiency, surpassing our previous milestone of 33.2%. We hope that our new achievement will contribute to accelerating the green energy transition. The recent champion cell was certified at European Solar Test Installation (ESTI) Center.”

New efficiency world record, June 2023

Only in the beginning of April, researchers from the KAUST Photovoltaic Laboratory (KPV-Lab) at the KAUST Solar Center produced a perovskite/silicon tandem solar cell with a power conversion efficiency (PCE) of 33.2 %, topping the world record recently set by the Helmholtz-Zentrum Berlin (HZB).

A team of researchers at the National Centre for Photovoltaic Research and Education (NCPRE) at the Indian Institute of Technology Bombay (IITB) has fabricated a semi-transparent perovskite solar cell (PSC) that, by combining it with a silicon-based solar cell, has demonstrated an efficiency of more than 26% for such a cell.

The team at IIT Bombay has addressed the stability issue by combining their PSC with a silicon solar cell in a tandem configuration. Combining the two different types of solar cells allows the device to convert more of the light falling on it into electricity. Apart from the higher efficiency, the tandem architecture also provides greater stability to the device, while driving its overall lifetime costs low.

Researchers from Saudi Arabia's King Abdullah University of Science and Technology (KAUST) have conducted a series of tests to see if the temperature coefficient of the short circuit current in perovskite-silicon tandem solar cells could be a proper standard of measurement to analyze their behavior and performance. The team has come to the conclusion that it may not be considered a proper metric to assess these devices’ performance and behavior.

The scientists explained that the idea of their recent paper was to show that the temperature coefficient of the short circuit current, measured under standard illumination conditions, might not well describe the actual operation of tandem solar cells. Depending on the local spectrum and the temperature range, the current at maximum power (Impp) can increase, decrease or have a mixed behavior. This intriguing effect can help the community to better understand their outdoor data as outdoor tandem operation should become more and more common in the next years.

The National University of Singapore (NUS) and REC Solar, the solar power arm of the Singaporean Renewable Energy Corporation, have launched a S$77 million (US$57.4 million) solar cell research initiative.

The project, called the REC@NUS Corporate R&D Laboratory for Next Generation Photovoltaics, will be led by two co-directors, professor Amrin Aberle, CEO of the NUS’ Solar Energy Research Institute of Singapore, and Shankar G Sridhara, chief technology officer of REC Solar. The university announced that the initiative will develop and commercialize “disruptive” PV technologies, based on perovskite-silicon tandem solar cells in particular.

LONGi announced new conversion efficiency of 33.5% for silicon-perovskite tandem solar cells based on commercial CZ silicon wafers, as was revealed at the Intersolar Europe 2023 exhibition. Earlier this month, LONGi announced its “STAR Innovative Ecological Cooperation Platform” and its newly achieved efficiency of 31.8% for perovskite/crystalline silicon tandem solar cells based on commercial CZ silicon wafers.

“Improving cell conversion efficiency and reducing the cost of electricity remain the perpetual theme driving the development of the photovoltaic industry.” Said Li Zhenguo, President of LONGi.