Researchers at the Chinese Academy of Sciences (CAS), Beijing Normal University, Beijing Institute of Technology and ShanghaiTech University have developed a universal hydrogen-bonding-facilitated DMA extraction method to fabricate high-quality γ-CsPbI3 films. The researchers fabricated a solar cell based on cesium-lead iodide (CsPbI₃) perovskite, which is also known as black perovskite.

The black perovskite solar cell reportedly achieved  20.25% efficiency, which is said by the team to be the highest efficiency reported for PV devices built with this perovskite material and a dopant-free hole transport layer based on the P3HT polymer. The cell was also able to retain around 93% of its original efficiency after continuous illumination for 570 h.

Inverted perovskite solar cells (PSCs) can deliver enhanced operating stability compared to their 'normal'-structure counterparts. To improve efficiency further, it is vital to combine effective light management with low interfacial losses. Now, scientists at Northwestern University, University of Kentucky, North Carolina State University, University of Toronto, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Peking University have developed a conformal self-assembled monolayer (SAM) as the hole-selective contact on light-managing textured substrates. 

The team reported that molecular dynamics simulations indicate cluster formation during phosphonic acid adsorption leads to incomplete SAM coverage. They devised a co-adsorbent strategy that disassembles high-order clusters, thus homogenizing the distribution of phosphonic acid molecules, thereby minimizing interfacial recombination and improving electronic structures.

In an effort to tackle the challenge of perovskite solar cells' thermal instability, researchers at City University of Hong Kong (CityU), National Renewable Energy Laboratory (NREL) and Huazhong University of Science and Technology have developed a unique type of self-assembled monolayer, or SAM for short, and anchored it on a nickel oxide nanoparticles surface as a charge extraction layer. This method dramatically enhanced the thermal robustness of perovskite solar cells, according to Professor Zhu Zonglong of the Department of Chemistry at CityU.

“By introducing a thermally robust charge extraction layer, our improved cells retain over 90% of their efficiency, boasting an impressive efficiency rate of 25.6%, even after operated under high temperatures, around (65℃) for over 1,000 hours. This is a milestone achievement,” said Professor Zhu.

Existing fabrication processes for creating efficient metal halide perovskite solar cells (PSCs) require an inert (i.e., chemically inactive) atmosphere, such as that within a nitrogen glovebox. Recently, researchers from China's North China Electric Power University have introduced a strategy to create PSCs with PCEs above 25% in ambient air. 

This strategy is hoped to accelerate commercialization of PSCs. "The fabrication of perovskite solar cells (PSCs) in ambient air can accelerate their industrialization," Luyao Yan, Hao Huang and their colleagues wrote in their paper. "However, moisture induces severe decomposition of the perovskite layer, limiting the device efficiency. We show that sites near vacancy defects absorb water molecules and trigger the hydration of the perovskite, eventually leading to the degradation of the material." To fabricate their solar cells in ambient air conditions, the scientists blocked the pathway through which perovskite layers can become hydrated and consequently suffer severe damage. They did this using the acetate salt form of the chemical compound guanabenz, known as GBA.

This is a sponsored post by Ergis Group

In 2020, Poland-based Ergis Group launched the noDiffusion film platform, a high-barrier film that offers high level of optical transmittance and low level of light scattering, and the ability to contain transparent conductive electrodes. The new technologies adopted in the production of the barrier films offer a combination of high performance and competitive pricing.

Following years of R&D, Ergis is ready to enter production with its first-gen barrier films, produced using sputtering in a roll-to-roll (R2R) configuration. The company reports performance of around 10^-4 wtr performance for its barrier. This is referred to as a "light-barrier" and one that is more than enough for the encapsulation of perovskite materials. The company collaborated with Poland-based Saule Technologies to develop this specific film. Ergis is now shipping barrier film samples to its customers.

Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) and the University of Toledo have found that perovskite solar cells should be subjected to a combination of stress tests simultaneously to best predict how they will function outdoors.

The team used a state-of-the-art p-i-n PSC stack (with PCE up to ~25.5%) to show that indoor accelerated stability tests can predict 6-month outdoor aging tests. Device degradation rates under illumination and at elevated temperatures are most instructive for understanding outdoor device reliability. The team also found that the indium tin oxide (ITO)/self-assembled monolayer (SAM)-based hole transport layer (HTL)/perovskite interface most strongly affects the device operation stability. Improving the ion-blocking properties of the SAM HTL increases averaged device operational stability at 50°C–85°C by a factor of ~2.8, reaching over 1000 h at 85°C and to near 8200 h at 50°C with a projected 20% degradation, which is among the best to date for high-efficiency p-i-n PSCs.

Researchers from the Indian Institute of Technology Bombay and Germany's Helmholtz Young Investigator Group FRONTRUNNER IEK5-Photovoltaik have designed an inverted perovskite solar device that uses a self-assembled monolayer to suppress nonradiative recombination at the interface between the perovskite absorber and the hole transport layer. The team reported high efficiency for the cell and say it was also able to retain the initial efficiency rating for 3,000 h.

The inverted perovskite solar cell was based on a hole transport layer (HTL) made of a phosphonic acid called methyl-substituted carbazole (Me-4PACz).

Researchers from Princeton University and the King Abdullah University of Science and Technology (KAUST) have connected silicon solar cells with perovskite ones in a tandem solar cell to not only boost overall efficiency, but also to strengthen stability. The results show that the connection protects the frail perovskite solar cell from voltage-induced breakdown while attaining greater efficiencies than either cell can achieve on its own.

The team demonstrated that the tested perovskite/silicon tandem devices are considerably more resilient against reverse bias compared with perovskite single-junction devices. The origin of such improved stability stems from the low reverse-bias diode current of the silicon subcell. This translates to dropping most of the voltage over the silicon subcell, where such a favorable voltage distribution protects the perovskite subcell from reverse-bias-induced degradation.

Researchers from Pennsylvania State University have developed a cost-effective method for creating bio-inspired solar devices that could improve the performance of perovskite solar technology. The team drew inspiration from cell membranes, the protective barriers around cells in all living organisms.

The researchers combined perovskite solar cell material with a synthesized version of natural lipid biomolecules to help protect against moisture-induced degradation. These biomolecules are fatty or waxy materials that don’t dissolve in water. The biomolecules formed a membrane-like layer around the perovskite, boosting stability and efficiency in tests. The approach could have a great impact on how perovskite solar cells are designed.

It was reported that Sekisui Chemical, a Japanese plastics maker, will begin mass production of perovskite solar cells (PSCs) in an effort to catch up with Chinese competitors.

The company will invest more than 10 billion yen (over USD $68 million) to build a new manufacturing facility with an annual production volume of several hundred thousand square meters by 2030.