Efficiency

Recently, a University of Louisville team of researchers used nanoparticle inks by Sofab Inks (a U of Louisville spinout) to create PSCs with ~20% PCE on flexible substrates. Their study addresses the solvent scope and perovskite compatibility of acetate-stabilized yttrium-doped SnO₂ (Y:SnO₂) dispersions.

Tin oxide (SnO₂) stands out as a compelling electron transport material (ETM) for perovskite solar cells (PSCs), boasting exceptional optoelectronic properties, coupled with low-temperature solution processability, cost-effectiveness, and remarkable stability. However, the widespread application of SnO₂ has been hindered by solvent incompatibilities, limiting its use to devices where it is deposited beneath the perovskite layer. To unlock the full potential of SnO₂ and expand its use across various device structures, including inverted PSCs and tandem devices, innovative deposition strategies will need to be developed. These advancements could pave the way for more efficient and versatile solar cell designs, pushing the field of photovoltaics forward.

The scientists showed that dispersions in several lower alcohols and select polar aprotic solvents can be directly deposited on perovskite using scalable and low-temperature processes. In addition, they are compatible with various perovskite formulations, including those with mixed cations and mixed anions.

It was reported that China-based Risen Energy, a company primarily focused on grid-connected PV power generation systems, announced its new achievement in the research and development of perovskite and HJT tandem solar cells. A power conversion efficiency of 30.99% was reportedly achieved by Risen Energy’s R&D institution, and the result was confirmed by the China National Center of Supervision and Inspection on Solar Photovoltaic Products Quality (CPVT).

As a leading solar module manufacturer in China, Risen Energy believes that HJT solar cells with unique structure and features are promising products among p-type and n-type single junction solar cells. HJT’s advantages are significant in perovskite and silicon tandem solar cells, making it naturally suitable as a base for tandem cells. HJT is seen as one of the best bottom cells for crystalline silicon and perovskite tandem cells. Other types of crystalline silicon cells, due to the lack of ITO film, require redesign of the structure prior to tandem processing, which increases cost and complexity.

Researchers from Singapore's Nanyang Technological University and France's University of Lille (CNRS) have developed a biomass-derived furan-based conjugated polymer, PBDF-DFC, enabling a simplified direct precursor integration fabrication method for hybrid perovskite solar cells (HPSCs). 

Unlike traditional thiophene-based polymers, PBDF-DFC reportedly exhibits high solubility in perovskite precursor solvents, allowing direct incorporation into the precursor solution. This direct precursor integration approach could significantly streamline the fabrication process, reducing steps and potentially lowering production costs. 

An international team, including researchers from EPFL, CNR SCITEC, Fujian Normal University, Southern University of Science and Technology (SUSTech) and others, has used an n-type polymeric additive to stabilize C60 molecules for use in inverted perovskite solar cells. The researchers reportedly designed a solar cell with the highest efficiency value ever recorded for perovskite devices based on solution processed C60 electron transport layers.

The team explained that C60 is currently the best-performing type of ETL for perovskite solar cells, although it suffers from “significant” aggregation in solution, which makes a high-cost and complex thermal evaporation method necessary for its development. To solve this issue, it utilized an n-type polymeric additive to stabilize C60 molecules for solution processing. “We introduced an n-type polymeric additive, TPDI-BTI, constructed from the strongly electron-deficient dithienylpyrazinediimide (TPDI) and the imide-functionalized bithiophene (BTI) co-unit and applied it into the C60 ETLs,” the researchers explained. “By controlling the TPDI-BTI addition, we can systematically regulate the ETLs, including film formability and morphological stability, energy levels and electron transport dynamics, intermolecular interacting behaviors and interfacial contacts, and finally, the photovoltaic performance and long-term stability of the cells.”

Perovskite solar cell developer, SolaEon Technology, has announced that its all-perovskite tandem solar cells, co-developed with Shanghai Jiao Tong University, have achieved a certified conversion efficiency of 30.58%. 

SolaEon says this achievement has been verified by the China Photovoltaic Testing Center (CPVT). The maximum power point tracking (MPPT) stabilized efficiency for these cells reached 30.49%, which the company claims is a new efficiency record for this technology.

Microquanta has reportedly announced that its 810 cm² medium-sized perovskite module has achieved a certified full-area power conversion efficiency of 21.86% (average of forward and reverse scan: 21.83% forward, 21.89% reverse), as verified by the National PV Industry Measurement and Testing Center (NPVM).

The company called this a new efficiency record for perovskite modules of this size. Microquanta stated that the module incorporates its proprietary cryogenic laser repair technology, which in addition to significantly enhancing module efficiency also greatly improves module stability. Microquanta plans to apply this technology to its upcoming GW-scale perovskite production line, set to commence operations in March this year. The company has set a target of surpassing 20% conversion efficiency and achieving a 25-year lifespan for large-area modules with a size of 2.88 m².

Smartline PV is an innovative Horizon Europe project focused on improving the efficiency and stability of tin halide perovskite solar cells, a promising alternative to toxic lead-based systems. The project focuses on overcoming key challenges with a fast, robust, and scalable plasma-assisted crystallization technology, which ensures high-quality tin perovskite films through precise control of nucleation and growth. This innovative process benefits from high speed, low temperatures, and tailored precursor chemistry.

Additionally, Smartline PV will implement tailored interlayers to further enhance solar cell efficiency and stability, along with novel device concepts for flexible, color-selectable tin perovskite solar cell modules. Smartline PV's lead-free technology aims to achieve efficiencies of 22%, significantly reducing energy consumption and manufacturing costs compared to traditional high-temperature thin film processes.

Researchers from China's Westlake University, Advanced Solar Technology Institute of Xuancheng and Turkey's Marmara University have addressed the stability issues of perovskite solar cells (PSCs) by developing a divalent cation replacement strategy that mitigates ionic migration while limiting phase segregation. 

Using the new method, the scientists fabricated a champion cell that showed a PCE of 23.20% (certified 22.71%) for a single-junction PSC with a bandgap between 1.67 eV and 1.68 eV. Furthermore, a PCE of 30.13% was obtained for mechanically stacked perovskite/Cu(In,Ga)Se₂ tandem devices, and a PCE of 21.88% for transparent perovskite devices. Finally, they obtained a steady-state PCE of 23.28% (certified 22.79%) for flexible monolithic perovskite/Cu(In,Ga)Se₂ tandem cells.

A Japanese consortium that includes three companies is testing the durability and performance of lightweight, flexible perovskite solar modules at Osanbashi Pier, Yokohama City in windy and salt-air conditions. The outdoor trial is part of a larger 3-year perovskite solar technology research collaboration.

Demonstration location: Large Pier (owned and designated by Yokohama City Port Bureau). Image credit: Macnica

The three-month 1 kW perovskite solar module trial on Osanbashi Pier began in November 2024. The three Japan-based companies that are participating in the outdoor seaport demonstration are: Macnica, a technology and electronics supplier, Reiko, a thin film product manufacturer, and perovskite solar cell specialist Peccell Technologies, which was founded in 2004 as a Toin University of Yokohama spin-off by perovskite solar cell pioneer Tsutomu Miyasaka.

Scientists from HZB and Humboldt University Berlin have reported a CIGS-perovskite tandem cell that sets a record with an efficiency of 24.6%, certified by the independent Fraunhofer Institute for Solar Energy Systems.

The team's new tandem solar cell combines a bottom cell made of CIGS with a top cell based on perovskite. By improving the contact layers between the top and bottom cells, they were able to increase the efficiency to 24.6%. This cell was the result of a successful team effort: the top cell was fabricated by TU Berlin master's student Thede Mehlhop under the supervision of Stefan Gall. The perovskite absorber layer was produced in the joint laboratory of HZB and Humboldt University of Berlin. The CIGS sub-cell and contact layers were fabricated by HZB researcher Guillermo Farias Basulto. He also used the high-performance cluster system KOALA, which enables the deposition of perovskites and contact layers in vacuum at HZB.