Efficiency

Researchers from Northwestern University, Arizona State University, University of Toronto and National University of Singapore have addressed the issue of ion migration, which deteriorates the performance and stability of perovskite solar cells (PSCs). The team has developed a new method to improve the stability and efficiency of PSCs through surface functionalization, which uses a chemical compound called 5-ammonium valeric acid iodide (5-AVAI) to enable the uniform growth of aluminum oxide (Al₂O₃) through atomic layer deposition. This process creates a robust barrier that suppresses halide migration by more than an order of magnitude.

Using this method, the researchers tested solar cells, and found that they retained 90% of their initial power conversion efficiency (PCE) after 1,000 hours of continuous operation at 55 degrees Celsius under full sunlight, compared to less than 200 hours without the barrier layer. 

Researchers from Pakistan's University of Engineering & Technology (UET) and National University of Technology have reported the use of manual screen printing to fabricate semi-transparent, scalable perovskite solar modules without the requirement for numerous laser-scribing steps. 

A carbon-based, hole-transport-layer-free perovskite solar module with a power conversion efficiency of 11.83% was manufactured, with an active area of 900 cm². Accelerated testing was done in settings with elevated humidity, high sun irradiation, and harsh temperatures to determine whether these modules are ready for the market. 

The interfaces of each layer in perovskite solar cells (PSCs) have a significant impact on the charge transfer and recombination. Especially, the interface between perovskite and the hole transport layer (HTL) in p-i-n type PSCs significantly affects the contact characteristics between the HTL and perovskite, hindering further improvements in performance and stability. 

Researchers from South China University of Technology and Guangxi University have introduced a small molecule 9-Fluorenylmethoxycarbonyl chloride (9-YT) as a molecule bridge for p-i-n PSCs, which enhances the interaction between self-assembly molecules (SAMs) and perovskite. 

JinkoSolar has announced that it has achieved a significant breakthrough in the development of its N-type TOPCon-based perovskite tandem solar cell. Independently tested by the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, the cell achieved an impressive conversion efficiency of 33.84%, surpassing JinkoSolar's previous record of 33.24%. This achievement marks the 27th time JinkoSolar has set a world record for efficiency and power output for PV products.

The record-breaking perovskite tandem solar cell utilizes JinkoSolar's N-type high-efficiency monocrystalline TOPCon solar cell as the bottom cell, enhanced by significant advancements across multiple key technologies. Innovations such as full-area passivated contact technology, perovskite interfacial defect passivation technology, and bulk defect passivation technology have contributed to the enhanced efficiency of the perovskite/TOPCon tandem cell. This achievement highlights the compatibility of TOPCon as a mainstream solar cell technology with the next-generation perovskite/silicon tandem cell technology, paving the way for new possibilities in the future development of the photovoltaic industry.

It was reported that Kunshan GCL Photoelectric Materials (GCL Perovskite), a subsidiary of GCL Tech, has announced that it has achieved a high photoelectric conversion efficiency of 22.43% on its large 2048cm² single-junction perovskite solar module. The result was verified by the China National Institute of Metrology.

GCL Perovskite’s R&D team has designed a technical solution to optimize module performance by not only reducing the series resistance of large area perovskite modules, but also significantly reducing the non-radiative compound loss. As a result, the fill factor (FF) of the 2048cm² large area perovskite monojunction module was increased to 82.3% and the efficiency to 22.43%, both of which are said to set new world records.

Researchers from Huaqiao University, City University of Hong Kong and Chinese Academy of Sciences (CAS) have explained that highly efficient perovskite solar cells in the n-i-p structure demonstrated limited operational lifetimes earlier due to the layer-to-layer ion diffusion in perovskite/doped hole-transport layer (HTL) heterojunction, leading to conductivity drop in HTL and component loss in perovskites. Now, they have reached 26.39% efficiency of perovskite solar cells using an ultrathin (~7 nm) p-type polymeric interlayer (D18) with excellent ion-blocking ability between perovskite and HTL to address these issues.

Device architecture, the structure of D18 polymer, and the detailed ion blocking effect of D18 membrane. Image credit: Nature Communications

The ultrathin D18 interlayer effectively inhibits the layer-to-layer diffusion of lithium, methylammonium, formamidium, and iodide ions. Additionally, D18 improves the energy-level alignment at the perovskite/HTL interface and facilitates efficient hole extraction. 

Hanwha Solutions Qcells Division (Hanwha Qcells), a global leader in complete clean energy solutions, has announced a new world record, reaching 28.6% for tandem solar cell efficiency on a full-area M10-sized cell that can be scaled for mass manufacturing. This result was achieved despite having only begun large-area tandem development in 2023.

“The tandem cell technology developed at Hanwha Qcells will accelerate the commercialization process of this technology and, ultimately, deliver a great leap forward in photovoltaic performance,” said Danielle Merfeld, Global CTO at Hanwha Qcells. “We are committed to advancing the next generation of solar energy efficiency and will keep investing significantly in research and development to drive progress in this field, as every kilowatt counts on the path to building a more sustainable future.”  

Nexwafe, a German wafer manufacturer, said that a perovskite-silicon tandem solar cell it developed in partnership with the Swiss Center for Electronics and Microtechnology (CSEM) has achieved a power conversion efficiency of 28.9%.

The tandem perovskite 2-junction cells used NexWafe’s EpiNex wafers and demonstrated their potential for advanced solar technologies. The company stated that with superior smoothness at the nano-scale, EpiNex wafers provide the ideal platform for the next generation of low-cost, solution-processed tandem perovskite cells.

In November 29, Hangzhou Xianna Optoelectronic Technology Co., Ltd. delivered its perovskite α-tandem modules for the China Three Gorges New Energy 50 MW PV demonstration project, in what is said to mark the first commercial application of four-terminal perovskite-silicon tandem modules in China. 

Once the PV power plant utilizing these tandem modules is completed and connected to the local grid, it will significantly alleviate the local grid's supply-demand imbalance, reduce environmental pollution, and improve air quality. The design work for a 500 kW demonstration plant has already been completed, with plans to collaborate with engineering institutes for on-site module layout design. The demonstration plant is expected to be connected to the grid and operational by the end of 2024.

Researchers from China's Tianjin University of Technology, Zhejiang Sci-Tech University, University of Electronic Science and Technology of China, North China Electric Power University and South China University of Technology have shown that the introduction of azetidinium iodide (AZI) into the precursor solution of a 1.77 eV bandgap FA_0.8Cs_0.2Pb(I_0.6Br_0.4)₃ perovskite significantly improves the efficiency and stability of the perovskite cells. 

Devices fabricated with 2 mol% AZI (relative to FAI, noted as AZ2) in perovskite layer exhibited a high PCE of 19.16 % and a high open-circuit voltage of 1.31 V. When stored under nitrogen atmosphere and illuminated under 1 sun conditions for 300 h, AZ2 device retained 80 % of the initial values.