US Researchers Achieve Record 25.1% Efficiency with Large Perovskite-Silicon Tandem Solar Cell

US scientists have achieved a breakthrough in photovoltaic (PV) cell technology by creating a large-area perovskite-silicon tandem solar cell measuring 24 cm2. This tandem cell has achieved a remarkable steady-state power conversion efficiency of 25.1%. To overcome common issues associated with scaling up perovskite solar technologies, such as shunting losses that create alternate pathways for solar-generated charge and lead to power losses, the researchers inserted a lithium fluoride (LiF) interlayer between a hole transport layer (HTL) and a wide bandgap (WBG) perovskite absorber. This interlayer improves physical contact and reduces shunting. The tandem cell demonstrated an efficiency of 25.2% under standard conditions, making it one of the most efficient two-terminal tandem devices for areas exceeding 10 cm2. This development holds promise for efficient, reproducible, and large-scale perovskite-silicon tandem solar cells.

Current-voltage curves for a perovskite mini-module with an aperture area of 42.9 cm2 Image: University of North Carolina at Chapel Hil, Cell Reports Physical Science, Creative Commons License CC BY 4.0

ALD is an important technology in perovskite solar cell fabrication. It enables precise, nanoscale control of layer thickness, ensuring uniform coverage even on complex surfaces. ALD is used for depositing passivation layers to reduce defects and enhance stability, creating protective barriers against environmental factors, engineering interfaces for improved charge transport, and ensuring compatibility with various materials. These applications contribute to improving the efficiency and long-term stability of perovskite solar cells, making ALD an essential tool in their development and optimization.

For deployment in solar cells, "perovskite" denotes a particular class of materials employed as the light-absorbing layer. These perovskite solar cells utilize a group of materials characterized by a crystalline structure akin to that of the mineral perovskite, named after Russian mineralogist Lev Perovski. Typically, these materials are comprised of organic-inorganic hybrid compounds, with common examples including methylammonium lead iodide (CH3NH3PbI3) and formamidinium lead iodide (HC(NH2)2PbI3). Perovskite solar cells have garnered substantial interest due to their potential for high efficiency, cost-effectiveness in production, and simplified manufacturing processes. Researchers are diligently working to enhance the efficiency, stability, and scalability of perovskite solar cells to position them as a competitive and sustainable renewable energy solution.

Source: Large-area perovskite-silicon tandem PV cell hits record efficiency of 25.1% – pv magazine International (pv-magazine.com)

Dutch Scientists at TNO & TU Eindhoven Develop Efficient Monolithic Perovskite-PERC Tandem Solar Cell

Highlights

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  Champion 23.7% efficient perovskite-PERC tandem cell was achieved.

• •

  The developed thermal atomic layer deposition (ALD) process for NiO is reported.

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  ALD NiO was added to an ITO/SAM recombination junction to improve the device yield.

Dutch researchers at TNO and TU Eindhoven have achieved a notable breakthrough in solar cell technology by creating a monolithic perovskite-PERC tandem solar cell with a remarkable 23.7% efficiency. The innovation lies in a new tunnel recombination junction (TRJ) design that includes indium tin oxide (ITO), carbazole (2PACz), and a nickel(II) oxide (NiO) layer. Unlike conventional TRJs, the addition of NiO significantly reduces electrical issues in the perovskite top cell.

(a) HAADF-scanning transmission electron microscopy (TEM) image of a tandem cell using ITO/NiO/2PACz. (b) Compositional line profiles at the interface ITO/NiO/SAM extracted from an EDX elemental mapping. Note that the figure is rotated 90°.

By using atomic layer deposition (ALD), the team improved the uniformity of the self-assembled monolayer (SAM) in the TRJ structure. This new solar cell design includes a perovskite absorber, electron transport layers, an ITO electrode, a silver (Ag) metal contact, and an antireflective coating.

Comparing their creation with a reference cell, the researchers found the novel TRJ-based cell achieved an efficiency of 23.7%, slightly below the reference cell's 24.2%. However, the novel design's uniform coverage of SAM and consistent efficiency across different devices within and between batches makes it promising for large-scale production.

Published in Solar Energy Materials and Solar Cells, this research opens doors for improved perovskite-PERC tandem solar cell technology using ALD NiO.

Atomic layer deposition of NiO applied in a monolithic perovskite/PERC tandem cell - ScienceDirect

ALD coatings for next-generation solar cells

(Helsinki : LINK) Researchers at the University of Helsinki are developing thin films needed in new types of halide perovskite solar cells, and matching ALD processes, in order to provide increasingly affordable solar cells, enable their integration into objects and, consequently, promote the transition to renewable energy.

The 2022 Millennium Technology Prize has been awarded today October 25 to Scientia Professor Martin Green of the UNSW Sydney, Australia, for his innovation that has transformed the production of solar energy.

Members of the research group next to the ALD reactor. Georgi Popov (left), Marianna Kemell, Alexander Weiss and Mariia Terletskaia. (Image: Riitta-Leena Inki)

Most commercial solar cells are silicon-based, and apply PERC (Passivated Emitter and Rear Cell) technology originally launched in 1983 by Martin Green, a recently awarded Millennium Award. However, increasingly efficient, inexpensive and durable solar cells are being developed all over the world. Even in the case of silicon-based cells, a transition is underway to novel techniques, including the tunnel oxide passivated contacts (TOPCon) concept, where several layers of silicon and oxide are added to the cell.

Transparent and flexible solar cells

In addition to silicon, other solar cell technologies are being investigated. The most promising new technique is based on the use of halide perovskites as a light-absorbing material. The general chemical formula of halide perovskites is ABX₃, where A is an alkali metal or an amine, B is tin or lead, and X is a halide. The most commonly studied compound is methylammonium lead iodide CH₃NH₃PbI₃. Perovskite solar cells are on the verge of commercialisation, and some manufacturers believe they will be mainstream in a couple of decades.

“As these new types of solar cells can be transparent, they can be installed in, for example, windows. They are also flexible, which increases their uses,” says Senior University Lecturer Marianna Kemell, who heads the research project funded by the Academy of Finland.

Even though halide perovskite solar cells have achieved high efficiency levels, problems with cell stability and the lack of industrial-scale production techniques have constituted bottlenecks impeding their widespread adoption.

A breakthrough with metal iodides

While pursuing a master’s degree in chemistry, Doctoral Researcher Georgi Popov boldly chose halide perovskites and their atomic layer deposition (ALD) as the topic of his master’s thesis. There were doubters, as prior research-based knowledge was scarce.

“We identified suitable chemicals and were able to design a reaction that enabled us to create a metal iodide coating through deposition for the first time. We were able to demonstrate that this can actually be done through atomic layer deposition. The first successful trial was carried out with lead iodide, which was then processed into CCH₃NH₃PbI₃ perovskite through a further reaction,” Popov says. “The research article was published in the refereed Chemistry of Materials scholarly journal. Later on, we also developed ALD processes for caesium iodide and CsPbI₃ perovskite.”

Coatings produced through atomic layer deposition are used in roughly 30% of silicon-based solar panels. The ALD group headed by Professor Mikko Ritala at the University of Helsinki has achieved promising results in terms of the technique’s adaptability to perovskite solar cells. The advantage of coatings produced by atomic layer deposition is that they form a uniform and comprehensive layer even on rough surfaces.

“If at some point we start making tandem solar cells, which combine a silicon cell and a perovskite cell, we know how to make that perovskite. We are developing the recipes and the chemistry used to grow perovskite,” Popov says.

While the work currently being carried out is basic research, developing recipes and experimenting with small surface areas, the technique is applicable to large-scale production.

“The current plants manufacturing solar cells in China and elsewhere are able to adjust their equipment to produce ALD-coated solar cells,” says Popov.

The future of solar cells

More than 80% of solar cells are manufactured in China, where industrial-scale ALD devices are also produced. Wei-Min Li, PhD, an alum of the University of Helsinki’s Department of Chemistry, works as the chief technology officer at Leadmicro, a leading Chinese manufacturer of ALD equipment. This connection gives the department a solid grasp on where the field is going. ALD equipment used to produce silicon-based solar panels can also be expanded to produce next-generation solar cell materials.

“We are developing the future technical solutions that will gradually replace and supplement current production. In the future, fewer resources will be needed for production, and, thanks to increasingly effective cells, less surface area as well. When solar cells can be installed on uneven surfaces in addition to even ones, we no longer need to build solar parks in fields, as fields are needed for other purposes,” Popov notes.

However, Popov points out that we cannot afford to wait for new technical solutions, as the utilisation of renewable energy sources must be increased now. By replacing current sources of energy with solar or wind power as much as possible, pressure will increase and the entire field will advance.

“The best part of silicon-based cells is that they last roughly 20 to 30 years and will continue to function even after that, albeit possibly less efficiently. Since solar cells produced with the PERC technique are the current state of the art, and they are available, it is advisable to acquire as many of them as possible. They will pay for themselves,” Senior University Lecturer Kemell says.

The project entitled ‘Atomic Layer Deposition as key enabler of scalable and stable perovskite solar cells’, which is funded by the Academy of Finland, will continue until 2024. In addition to Marianna Kemell and Georgi Popov, contributing to the project are Doctoral Researcher Alexander Weiss and master’s student Mariia Terletskaia.

New world records: perovskite-on-silicon-tandem solar cells

EPFL and CSEM smash through the 30% efficiency barrier for perovskite-on-silicon-tandem solar cells —setting two certified world records 

Neuchâtel, July 7, 2022 – For the first time, an efficiency of 30% for perovskite-on-silicon-tandem solar cells has been exceeded thanks to a joint effort led by scientists at EPFL’s Photovoltaics and Thin Film Electronics Laboratory in partnership with the renowned innovation center, CSEM. Independently certified by the National Renewable Energy Laboratory (NREL) in the United States, these results are a boost to high-efficiency photovoltaics (PV) and pave the way toward even more competitive solar electricity generation.

Left and right panels: Schematics of perovskite-on-silicon tandems that are either flat or textured on their front side. Upper central panels: scanning electron microscopy images of the two types of devices developed by EPFL and CSEM. Lower central panels: corresponding picture. Credit: D. Türkay (EPFL), C. Wolff (EPFL), F. Sahli (CSEM), Q. Jeangros (CSEM).

More information: LINK

By Abhishekkumar Thakur 

Solar Energy Research Institute of Singapore (SERIS) Opts for SALD

The Solar Energy Research Institute of Singapore (SERIS) gears up perovskite solar cells for industrial tandem cell production

Eindhoven/Netherlands, Singapore, 18 June 2022 - The Solar Energy Research Institute of Singapore (SERIS) at the National University of Singapore (NUS) announces that it will upgrade its "Spatial Atomic Layer Deposition" (SALD) equipment. SoLayTec and SERIS have been working closely together for over a decade in the field of silicon solar cells. Now, SERIS states that SoLayTec will upgrade its existing ALD system using the latest technology of SALD BV, a Dutch technology start-up, for development of scalable perovskite-silicon tandem solar cells.

"Upgrading to the new SALD equipment brings us significant advantages," explains Dr. Shubham Duttagupta, Deputy Director of the Next-Generation Industrial Solar Cells & Modules Cluster at SERIS. The Dutch company SALD BV has developed a unique, patented technology for applying precise coatings on an industrial scale that can be as thin as a single atom. These so-called nanocoatings are promising to revolutionize numerous industrial manufacturing processes, and thus entire branches of industry. In the solar industry, SALD coatings are key for perovskite-silicon tandem solar cells, which can achieve efficiencies far above the theoretical limit of silicon-only solar cells, which are the most widely used solar cells today. It is precisely in this new area where SERIS aims to use the new SALD technology. Thanks to the SALD process, new solar cell materials can be used, including tin oxide and transparent conductive oxides, as well as novel passivation and tunnel recombination layers. The technologies developed by SERIS will be made available to industrial solar cell manufacturers through licensing agreements.

Perovskite solar cells are highly efficient, easy to process and inexpensive to produce, but still face technical challenges regarding their long-term stability. An atomically thin coating, as can be achieved with the SALD technology, makes the cells significantly more robust. SERIS wants to take the leap “from lab to fab”, i.e., from the laboratory environment to large-volume production with the new SALD machine. The potential for perovskite-silicon solar cells is great: According to forecasts, the global market is expected to exceed two billion dollars by 2027.

SALD BV has developed a unique worldwide patented technology for applying coatings that are as thin as a single atom on an industrial scale, termed "Spatial Atomic Layer Deposition" or SALD (www.spatialald.com). These atomically-thin coatings can bring revolutions to entire industries, such as the manufacturing of batteries for cars and smart devices, and the solar energy industry.

Further information: SALD BV, PO Box 520, 5600 AM Eindhoven, The Netherlands,

Web: www.spatialald.com, E-Mail: info@spatialald.com, Tel: +31 40 23 80 500,

contact: Lonneke van Wel, Tel. +31 40 238 05 00, E-mail: lonneke.vanwel@spatialald.com

PR-Agent: euromarcom public relations, Tel. +49611-973150, E-Mail: team@euromarcom.de, Internet: www.euromarcom.de, www.facebook.com/euromarcom (like if you like-:)

UNIST has set a new efficiency record for a perovskite solar cell (PSC) at 25.8%

[UNIST] A research team, led by Professor Sang Il Seok in the School of Energy and Chemical Engineering at UNIST has set a new efficiency record for a perovskite solar cell (PSC) at 25.8% by forming an interlayer between electron-transporting and perovskite layers to minimize interfacial defects, contributing to the decrease in the power conversion efficiencies. The new record, according to the research team, is the world’s highest power conversion efficiency (PCE) reported so far. Besides, the record, certified by National Renewable Energy Laboratory (NREL), is also the highest confirmed conversion efficiency of 25.5%.

In perovskite solar cells, the interfaces between the perovskite and charge-transporting layers contain high concentrations of defects, specifically deep-level defects, which substantially reduce the power conversion efficiency of the devices, noted the research team. Efforts have been made to reduce these interfacial defects have focused mainly on surface passivation. Yet, passivating the perovskite surface that interfaces with the electron-transporting layer has been difficult, because the surface-treatment agents on the electron-transporting layer may dissolve while coating the perovskite thin film.

“Alternatively, interfacial defects may not be a concern if a coherent interface could be formed between the electron-transporting and perovskite layers,” said the research team.

Continue reading: Perovskite Solar Cells with Atomically Coherent Interlayers on SnO2 ElectrodesUNIST News Center | UNIST News Center

The findings of this research have been published in the October 2021 issue of Nature. 

Journal Reference
Hanul Min, Do Yoon Lee, Junu Kim, et al., “Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes,” Nature (2021). Perovskite solar cells with atomically coherent interlayers on SnO2 electrodes | Nature

Perovskite Solar Cells by ALD with Georgi Popov Helsinki University

 

Georgi Popov, Helsingfors universitet, med presentationen "Perovskite Solar Cells by Atomic Layer Deposition (ALD)", del 2/8 i videoserien ”STV 100 år – fokus på energi” där unga forskare från olika högskolor och universitet i Finland presenteras sina forskningsprojekt inom ämnesområdet energi. Producent, regi och klipp: Johanna Stenback, All Things Content Fotograf och ljud: Anders Lönnfeldt 

Översättning: Andrea Reuter och Heidi Kråkström, All Things Content 

Svenska tekniska vetenskapsakademien i Finland, STV, firar sina första 100 år 2021. Redan vid akademiens sammankomst i mars 1922 berördes världsbehovet av energi. Temat är i nuläget aktuellt och många dagsaktuella problem kan lösas via smarta energilösningar. Vi har valt att energi är ett övergripande tema för vårt jubileumsår 2021 och också för vår videoserie. 

Hela serien med bakgrundsmaterial finns samlat på vår webbplats https://www.stvif.fi/stv-100-ar/ 

Doktoranden Gergi Popov har utvecklat flera experimentella metoder så att han kan använda tekniken atomavsättning, Atomic Layer Deposition (ALD), för att göra perovskita solceller. 

Denna nya typ av solceller består av tunna filmer och möter väl tillämpningar som kräver fysisk flexibilitet, genomskinlighet och avstämbara färger. Därtill är de billiga att producera av lättillgängliga material.

Tutorial - ALD for energy conversion and storage applications, Prof. Adriana Creatore - Eindhoven University of technology

Atomic Layer Deposition for energy conversion and storage applications by Prof. Adriana Creatore - Eindhoven University of technology. The tutorial was given at Solliance Day 2021 - 28 January 2021 Workshop sessions.

Scaled perovskite solar modules pass three critical stability tests

[Press release: LINK] Eindhoven (Netherlands), Genk (Belgium) January 23, 2020 – Solliance partners TNO, imec and the Eindhoven University of Technology, demonstrated encapsulated perovskite solar modules fabricated using industrial processes that withstand three established lifetime tests, i.e. the light soak test, the damp-heat test and the thermal cycling test. It is for the first time this milestone is passed with scaled perovskite solar modules prepared by research organizations.

Perovskite solar cells and modules, are nowadays widely acknowledged for their high efficiency values of up to 25.2% for the current latest record lab solar cell. Perovskite solar cells and modules combine high efficiency with low cost processability and are based on low cost and abundant materials. Furthermore, perovskite solar modules can be either rigid or flexible as well as opaque or semi-transparent. This allows a wide range of applications.

One can think of perovskite modules integrated in windows, roof tiles, facades, roads, noise barriers, car roofs – it is envisioned that these perovskite solar modules can be seamlessly integrated in an aesthetical manner with high social acceptance on any surface which receives light. Additionally, tandem solar modules consisting of a semitransparent perovskite module stacked on top of a conventional CIGS or silicon solar module can boost the overall efficiency to new record values.