Perovskite-Info: the perovskite experts

Researchers from Arizona State University’s Fulton Schools of Engineering have calculated that a 32% efficient perovskite-silicon tandem cell could produce electricity at the same price as cutting-edge 22% efficient panels in the most cost-competitive of situations.

The paper specifies: “…a large cost benefit will not necessarily be needed to prefer tandem systems over single-junction systems, because higher efficiencies bring additional perceived benefits such as reduced installation area. It is, however, necessary that the path leading to such a tandem be continuously profitable.”

A team of researchers from the University of Potsdam and HZB has identified loss processes in perovskite solar cells that limit their efficiency, and found that the most significant efficiency losses occur at the interface between the perovskite and transport layer.

In certain defects in the crystal lattice of the perovskite layer, charge carriers (i.e. electrons and "holes") that have been released by sunlight can recombine again and thus be lost. But whether these defects were located within the perovskite layer or at the interface between the perovskite layer and the transport layer was unclear until now.

Researchers at the University of Washington report that a prototype perovskite thin-film has performed even better than today’s best solar cell materials at emitting light. “It may sound odd since solar cells absorb light and turn it into electricity, but the best solar cell materials are also great at emitting light,” said co-author and UW chemical engineering professor Hugh Hillhouse. “In fact, typically the more efficiently they emit light, the more voltage they generate.”

a back-reflector A back-reflector surface used to test perovskite performance. Each quadrant is a different surface material — gold, titanium, palladium or a silica compound — upon which the perovskite material would be deposited for experiments

The UW team achieved a record performance using a lead-halide perovskite, by chemically treating it through a process known as “surface passivation,” which treats imperfections and reduces the likelihood that the absorbed photons will end up wasted rather than converted to useful energy.

Imec, the leading research and innovation hub in nanoelectronics, energy and digital technology, within the partnership of EnergyVille, announced a record result for its 4-terminal perovskite/silicon tandem photovoltaic cell. In fact, with a reported power conversion efficiency of 27.1%, the new tandem cell tops the most efficient standalone silicon solar cell. Further careful engineering of the Perovskite material will bring efficiencies over 30% in reach.

Imec’s new record tandem cell uses a 0.13 cm² spin-coated perovskite cell developed within the Solliance cooperation, stacked on top of a 4 cm² industrial interdigitated back-contact (IBC) silicon cell in a 4-terminal configuration, which is known to have a higher annual energy yield compared to a 2-terminal configuration. Additionally, scaling up the tandem device by using a 4 cm² perovskite module on a 4 cm² IBC silicon cell, a tandem efficiency of 25.3% was achieved, surpassing the stand-alone efficiency of the silicon cell.

Researchers at the Moscow State University named after MV Lomonosov, in cooperation with scientists from the Kurchatov Synchrotron Radiation Center, explained the key mechanisms of interaction of hybrid perovskites with solvents and based on the results obtained, suggested new approaches to obtaining a perovskite light-absorbing layer of thin-film solar cells from weakly coordinating aprotic solvents.

The scheme of transformations of perovskite components in solution proposed by the authors of the study

To apply thin films of perovskite from solutions, two solvents are usually used: dimethylsulfoxide and dimethylformamide. However, earlier work of MSU scientists showed that crystallization from them proceeds through the formation of intermediate compounds – crystal solvates, which can degrade the morphology and functional properties of the perovskite layer.

Researchers at the Technical Institute of Physics and Chemistry (TIPC) in China, together with research groups at Tianjin University and the University of California, have realized the fabrication of high-quality two-dimensional perovskite nanowire arrays, which exhibit ultra-sensitive photodetection.

Through controlling the dewetting dynamics on the asymmetric-wettability topographical interface, the researchers have realized the controllable growth of single-crystalline 2D-perovskite nanowires. These nanowires are self-organized layer-by-layer into quantum wells with alternating conductive perovskite layers and insulating organic cations.

New Energy and Industrial Technology Development Organization (NEDO) and Toshiba have announced the world's largest film-based perovskite photovoltaic module. The module is 703cm² (24.15 x 29.10cm) and achieves a power conversion efficiency (PCE) of 11.7%, overcoming the difficulties of increasing size and efficiency at the same time.

The module was developed using the meniscus printing technology owned by Toshiba and a newly developed printing process. Toshiba developed the printing process for a larger module by controlling the chemical reaction between PbI₂ and MAI on the substrate, using the ink composition as a mechanism. The company has also improved the uniformity of the layer thickness and increased the homogeneity of the crystal layer properties over a larger area, by controlling the process and adjusting the perovskite crystal growth conditions during the printing process. As a result, a PCE of 11.7% has been obtained on a module with an area of 703cm², almost as large as 900cm², the practical a scale.