Perovskite Solar

Solliance partners TNO, TU Eindhoven, imec and TU Delft have joined forces to further push the conversion efficiency of tandem solar cells to beyond the limits of today’s commercial PV modules. They have achieved an extraordinary feat: the first time that four-terminal perovskite/silicon tandem devices with certified top cell passed the barrier of 30%.

Bottom silicon solar cell and top perovskite solar cell with transparent contacts. Photo credit: Niels van Loon

Such high efficiency enables more power per square meters and less cost per kWh. The result was presented during the 8th World Conference on Photovoltaic Energy Conversion (WCPEC-8) in Milan and has been achieved by combining perovskite solar cell tech with conventional silicon solar cell technologies. The perovskite cell that features transparent contacts and is part of the tandem stack has been independently certified.

Researchers from Rice University, Northwestern University, Purdue University, University of Washington, CNRS and Argonne National Laboratory have addressed a long-standing issue in making stable, efficient solar panels out of halide perovskites. It took finding the right solvent design to apply a 2D top layer of desired composition and thickness without destroying the 3D bottom one (or vice versa). Such a cell would turn more sunlight into electricity than either layer on its own, with better stability.

The team, led by Chemical and biomolecular engineer Aditya Mohite and his lab at Rice’s George R. Brown School of Engineering, recently reported their success at building thin 3D/2D solar cells that deliver a power conversion efficiency of 24.5%.

Reliance New Energy, a wholly owned subsidiary of Reliance Industries, has signed agreements to invest in the US-based perovskite-based solar technology company Caelux Corporation which is in the research and development stage of its perovskite-based solar technology. 

The Reliance company will invest USD$12 million to acquire a 20 percent stake in the US-based company. 

Researchers from Korea University and Seoul Women's University have developed an inverted perovskite solar cell by introducing an electron-accepting interlayer at the interface between the perovskite layer and the electron transport layer.

The solar cell has a p-i-n structure (the perovskite cell material is deposited onto the hole transport layer and then coated with the electron transport layer), which is the opposite of the conventional n-i-p device structure. Inverted perovskite solar cells tend to show good stability, but lack in terms of conversion efficiency and cell performance.

Chinese equipment maker, Boamax Technologies Group, has announced a joint venture with researchers from Xidian University and another investor to develop and sell perovskite solar cells. The venture will also make production equipment and raw materials.

Boamax will have a 37% stake in the JV. A partnership formed by the Xidian  scholars will contribute its patent technologies to hold 45.5% of the equity. The third investor party will have an 18.2% stake. 

Researchers at University of North Carolina at Chapell Hill and University of Rochester have developed a novel hot gas-assisted method that could improve the fabrication of narrow bandgap (NBG) perovskite films for tandem solar cells. This strategy, combined with an anti-oxidation material added in the film, could increase the solar cells' carrier recombination lifetime (i.e., the time it takes for excess charge carriers to decay).

The researchers explained that all-perovskite tandem perovskite solar cells have the potential to reduce the cost of photovoltaic systems, due to their potential to reach a higher efficiency than their single-junction counterparts, while maintaining the solution fabrication processes. They said that compared to single junction perovskite modules, the application of tandem structures, which have much smaller photocurrents but higher photovoltage, can also reduce the cell-to-module efficiency derate and enable the realization of higher module efficiencies for monolithically interconnected modules in a series.

Researchers at CSIRO and Monash University have reported a flexible perovskite solar cell manufactured using roll-to-roll compatible “printing” type processes, which could potentially be used in large-scale manufacturing. To achieve this, the team developed a viable roll-to-roll process to deposit the electrode layer, which has thus far been a major challenge. The team managed to fabricated cells which achieved a maximum efficiency of 16.7%.

Photo: Hasitha Weerasinghe/CSIRO

Roll-to-roll processes signify a potential for low-cost manufacturing of flexible perovskites. However, adding the electrode layer in a process compatible with the roll-to-roll setup has proven to be a challenge. The research team in this recent work set out to address this issue and develop a process that could allow the electrode layer to be deposited without the need for solvents or heat treatments that potentially damage the perovskite layer as well.

Scientists from China's Jinan University, CoreTech Integrated Limited and Chinese Academy of Sciences have used selective nanosecond-pulse, laser-induced ablation to create a perovskite solar module with a reduced heat-affected zone.

The team showed that a nanosecond pulse laser can deliver a reduced heat-affected zone due to the small thermal diffusion coefficient (Dt) of the perovskite material, contributing to the accomplishment of a high geometric filling factor  (GFF) of up to 95.5%. In addition, the monolithic interconnection quality was improved by finely lifting off the capping layers on indium tin oxide and identifying the residue within the scribed area. As a result, a certified aperture area efficiency of 21.07% under standard 100 mW cm⁻² AM1.5G illumination was achieved with a high photovoltaic fill factor exceeding 80%.

Saule Technologies recently shared that its PESL (Perovskite Electronic Shelf Label) technology - electronic price and advertising labels powered by perovskite photovoltaic cells - have been installed at Żabka Eko Smart in Poznan, Poland. In addition, the same venue sports Saule's blinds that allow for generating energy from both natural and artificial light.

Saule shared that these unique technologies are aimed at improving the work of Żabka stores and increasing the comfort of customers and employees while maintaining care for the environment. 

A team of researchers from China's Tsinghua University, National Center for Nanoscience and Technology and Switzerland's Institute of Computational Physics (ICP) of the ZHAW School of Engineering have proposed a strategy to reduce defects and microstrains in perovskite films through multifunctional additives, achieving a record PCE of 23.6% for single-junction flexible perovskite solar cells (FPSCs).

Flexible perovskite solar cells (FPSCs) prepared on flexible substrates, which possess excellent flexibility and a high power-to-weight ratio, hold promise as a power source for wearable electronic devices, aerospace, and building integrated photovoltaics (BIPVs). Further improving the power conversion efficiency (PCE) and bending resistance of flexible devices is key to promoting their practical application.