Perovskite Solar - Page 20

Researchers from Wuhan University, University of South Florida, CNRS and Nanoneurosciences recently reported the first crystalline 2D Fullerene based Metal Halide Semiconductor, (C₆₀-2NH₃)Pb₂I₆.

Designing functionalized C60 adducts at the Spanopoulos Group at USF

According to the team, single crystal XRD studies elucidated the structure of the new material, while DFT calculations highlighted the strong contribution of C₆₀-2NH₃ to the electronic density of states of the conduction band of the material. Utilization of C₆₀-2NH₃ as an interlayer between a FA_0.6MA_0.4Pb_0.7Sn_0.3I₃ perovskite and a C60 layer reportedly offered superior band energy alignment, reduced nonradiative recombination, and enhanced carrier mobility.

Solaires Enterprises and XLYNX Materials recently announced a collaboration which will focus on building efficient and stable perovskite solar cells to “unlock the full potential of recycled light”. 

The partnership between the two Canada-based companies aims to help engineer the future of solar energy, according to Dr. Sahar Sam, a cofounder of Solaires Enterprises. “Through collaboration with XLYNX Materials, we are one step closer to making solar energy even more sustainable, cost-effective, and accessible,” Sam stated. 

Toray Engineering says that it will ship large size slot-die coaters for an upcoming Gigawatt scale (GW) perovskite production line. The first shipment is scheduled in the second quarter of 2024.

This upcoming production line will be the world’s largest perovskite PV production line, with a glass size of over 2 meters in size. Toray plans to ship multiple large-scale (over 2 meter) slot-die coaters in 2024 for perovskite production.

Toray Engineering’s slot-die coaters have already been used worldwide in perovskite coating processes in several installations. The company reports that market and customer demand is on the rise, and several companies are planning to construct large-area perovskite production lines, with glasses over 2.4 meters in size. Toray Engineering has produced and sold over 800 large-size slot-die coater systems, and is the only company that has successfully produced and shipped large slot-die coaters.

Researchers from Soochow University, Hunan University and Friedrich-Alexander University Erlangen-Nürnberg have incorporated pseudo-halogen thiocyanate (SCN) ions in iodide/bromide mixed halide perovskites and showed that they enhance crystallization and reduce grain boundaries. 

While perovskite/organic tandem solar cells could theoretically achieve high efficiency and stability, their performance is hindered by a process known as phase segregation, which degrades the performance of wide-bandgap perovskite cells and adversely affects recombination processes at the tandem solar cells' interconnecting layer. The team devised a strategy to suppress phase segregation in wide-bandgap perovskites, thus boosting the performance and stability of perovskite/organic tandem cells. This strategy entails the use of a pseudo-triple-halide alloy incorporated in mixed halide perovskites based on iodine and bromine.

An international group of researchers, led by the Chungbuk National University in South Korea, has reported a tin halide perovskite (Sn-HP) solar cell that uses an additive known as 4-Phenylthiosemicarbazide (4PTSC) to reduce imperfections in the perovskite layer.

Using wide bandgap tin halide perovskites (Sn-HP) could pose an eco-friendly option for multi-junction Sn-HP photovoltaics, but rapid crystallization often results in poor film morphology and substantial defect states, hampering device efficiency. The team's work aims to introduce a novel multifunctional additive to tackle these issues.

Researchers from Austria's Johannes Kepler University Linz have developed lightweight, thin (<2.5 μm), flexible and transparent-conductive-oxide-free quasi 2D perovskite solar cells by incorporating alpha-methylbenzyl ammonium iodide into the photoactive perovskite layer. 

The team fabricated the devices directly on an ultrathin polymer foil coated with an alumina barrier layer to ensure environmental and mechanical stability without compromising weight and flexibility.

Researchers from the University of Stuttgart, Lawrence Berkeley National Laboratory and Brandenburg University of Technology Cottbus-Senftenberg have introduced a simplified deposition procedure for multidimensional (2D/3D) perovskite thin films, integrating a phenethylammonium chloride (PEACl)-treatment into the antisolvent step when forming the 3D perovskite. 

The “traditional” deposition and passivation processes (top row) and the integrated deposition and passivation strategy to form 2D passivated 3D halide perovskite films (bottom row). Image from Advanced Materials.

This recently developed simultaneous deposition and passivation strategy reduces the number of synthesis steps while simultaneously stabilizing the halide perovskite film and improving the photovoltaic performance of resulting solar cell devices to 20.8%. 

Researchers at Austria's Johannes Kepler University Linz have developed lightweight, thin (<2.5 μm), flexible and transparent-conductive-oxide-free quasi-two-dimensional perovskite solar cells by incorporating alpha-methylbenzyl ammonium iodide into the photoactive perovskite layer. 

The team fabricated the devices directly on an ultrathin polymer foil coated with an alumina barrier layer to ensure environmental and mechanical stability without compromising weight and flexibility. 

Researchers from Helmholtz-Zentrum Berlin (HZB) and the University of Potsdam have analyzed surfaces and interfaces of CsPbI₃ films, produced under different conditions, at BESSY II. They found that annealing in ambient air does not have an adverse effect on the optoelectronic properties of the semiconductor film, but actually results in fewer defects. This could simplify the mass production of inorganic perovskite solar cells.

The best performing perovskite semiconductors contain organic cations such as methylammonium, which cannot tolerate high temperatures and humidity, so their long-term stability is still a challenge. However, methylammonium can be replaced by inorganic cations such as Cesium (Cs). Inorganic halide perovskites with the molecular formula CsPbX₃ (where X stands for a halide such as chloride, bromide and iodide) remain stable even at temperatures above 300 °C. CsPbI₃ has the best optical properties for photovoltaics (band gap ∼1.7 eV).

Researchers at NREL, BlueDot Photonics, University of Washington, Colorado School of Mines and Rochester Institute of Technology have developed a vapor deposition technique based on continuous flash sublimation (CFS) to fabricate all-inorganic perovskite thin films in under 5 minutes in a continuous process. The adoption of the proposed approach may also result in higher power conversion efficiencies of perovskite solar cell.

Schematic illustration of the continuous flash sublimation (CFS) approach consisting of a mechano-chemical synthesis of the source powder (here CsPb(I_xBr_1−x)₃), the high-throughput deposition process in a home-made evaporation system, and a short post-annealing treatment to improve thin-film quality. Image from Journal of Materials Chemistry A

The team described the new technique as a non-batch process that solves two problems associated with the use of established vapor processing in perovskite material manufacturing – the slow speed of deposition and the non-continuous nature of batch processing.