Hunt Perovskite Technologies (HPT), a Texas-based perovskite applications developer, has reported a milestone in the development of a highly-durable perovskite technology for the manufacture of low-cost printed solar cells.

In December 2019, HPT demonstrated that its ink-based process was able to produce a perovskite solar cell that exceeded key benchmarks recognized by the solar cell manufacturing industry and exceeded the International Electrotechnical Commission (IEC) durability thresholds in temperature, humidity, white light and ultraviolet (UV) stress testing while reaching efficiency performance levels of 18%.

Researchers at Saudi Arabia's King Abdullah University of Science and Technology (KAUST) claim to have improved the performance of solar cells based on inverted perovskites.

That type of cell has a device structure known as 'p-i-n', in which hole-selective contact p is at the bottom of intrinsic perovskite layer i with electron transport layer n at the top. Conventional halide perovskite cells have the same structure but reversed ' a 'n-i-p' layout. In n-i-p architecture, the solar cell is illuminated through the electron-transport layer (ETL) side; in the p-i-n structure, it is illuminated through the hole'transport layer (HTL) surface.

A new study led by Brown University finds that cracks in brittle perovskite films can be easily healed with compression or mild heating, a good sign for the use of perovskites in next-generation solar cells.

A cracked perovskite film (left) can be fully healed (right) with some compression of a little heat. Credit: Padture Lab/Brown University

'The efficiency of perovskite solar cells has grown very quickly and now rivals silicon in laboratory cells,' said Nitin Padture, a professor in Brown's School of Engineering and director of the Institute for Molecular and Nanoscale Innovation. 'Everybody's chasing high efficiency, which is important, but we also need to be thinking about things like long-term durability and mechanical reliability if we're going to bring this solar cell technology to the market. That's what this research was about.'

Researchers from three Japanese universities, led by Japan's Kanazawa University, have developed a process based on inkjet printing they say could reduce the cost of perovskite solar cell production. The group fabricated small cells with efficiencies as high as 13.19%, a figure they claim is promising enough to offer the possibility of scaling up to commercial production.

Schematic illustration of (a) the OEI setup used to pattern the TiO2 CL on FTO glass substrates and (b) the device structure of OEI-TiO2 CL-based PSCs.

The team has developed a process for depositing a titanium dioxide electron transport layer (ETL) onto a perovskite. The group claim the method could be scaled up to cut costs for manufacturers moving towards commercial perovskite cell manufacturing.

Researchers at the Massachusetts Institute of Technology (MIT) have conducted a techno-economic analysis they claim demonstrates the importance of niche markets for bringing cutting-edge PV technologies such as perovskites to commercial maturity.

Higher-value niche markets such as the building-integrated PV (BIPV) segment and self-powered microelectronics devices may offer more room for testing new solar technologies at lower cost, say the authors of the study. The MIT team said customers in such markets are more comfortable paying a higher price for more sophisticated products. 'They'll pay a little more if your product is flexible, or if the module fits into a building envelope,' stated the study.

An Empa team led by Frank Nüesch, Head of Empa's Functional Polymers Department, has been working in recent years on new manufacturing processes for perovskite solar cells in order to produce them not only faster but also cheaper. To this end, the researchers collaborated with Solaronix, a company based in western Switzerland, as part of a project of the Swiss Federal Office of Energy (SFOE). Together they produced a functional perovskite cell on a laboratory scale with a surface area of 10x10cm.

For the production of this novel perovskite cell, the so-called slot-die process is used. Here, the material layer is applied to a substrate of glass and then structured by removing excess material with a laser. "With the new coating process, we can not only coat faster, but also determine the thickness of the layers more flexibly," says Nüesch. In the future, the slot-die process will make it possible to coat meter-long webs relatively easily and quickly. The coating speed is then also the central element in a possible industrialization of perovskite cell production.

Panasonic Corporation has achieved an energy conversion efficiency of 16.09% for a perovskite solar module (Aperture area 802 cm²: 30 cm long x 30 cm wide x 2 mm thick) by developing lightweight technology using a glass substrate and a large-area coating method based on inkjet printing.

This was carried out as part of the project of the New Energy and Industrial Technology Development Organization (NEDO), which is working on the "Development of Technologies to Reduce Power Generation Costs for High-Performance and High-Reliability Photovoltaic Power Generation" to promote the widespread adoption of solar power generation.

The US Department of Energy (DOE) will allocate up to USD$125.5 million in financing for research and development (R&D) projects in the solar field. The research will target reducing the cost of solar technology, which in turn will enhance the competitiveness of the domestic photovoltaic (PV) production and improve the grid reliability.

Among other projects, the DOE funds will see USD$15 million go to 8-12 projects that aim to prolong the lifespan of PV systems and cut hardware costs for plants using traditional silicon solar cells, as well as thin-film, tandem and perovskite cells.

Scientists from Japan's Gifu University and the Tokyo Institute of Technology have identified a chalcogenide perovskite material with light absorption attributes strong enough to offer the potential for a theoretical maximum conversion efficiency of 38.7% in a silicon perovskite tandem solar cell.

The material ' BaZrTiS₃ ' has a light absorption coefficient exceeding 10⁵cm^-1, the highest of all solar cell materials including chalcogenide perovskites such as SrZrS₃, BaHfS₃ and SrHfS₃, the scientists claim.