A team at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a novel perovskites and CNTs-based demonstration device that responds to sunlight by transforming from transparent to tinted while converting sunlight into electricity.

A switchable photovoltaic window

The thermochromic windows technology responds to heat, as was said, by transforming from transparent to tinted. As the window darkens, it generates electricity. The color change is driven by molecules (methylamine) that are reversibly absorbed into the device. When solar energy heats up the device, the molecules are driven out, and the device is darkened. When the sun is not shining, the device is cooled back down, and the molecules re-absorb into the window device, which again appears transparent.

Australia-based GreatCell Solar, formerly known as Dyesol, was founded to develop, scale-up and commercialize 3rd generation solar PV technologies, and currently the company focuses on perovskite solar cell (PSC) materials and technologies.

GreatCell's Managing Director, Richard Caldwell kindly agreed to talk with Perovskite-Info about the Company's current technology and future plans - and his views on the perovskite market.

Australia-based GreatCell Solar, formerly known as Dyesol, was founded to develop, scale-up and commercialize 3rd generation solar PV technologies, and currently the company focuses on perovskite solar cell (PSC) materials and technologies.

GreatCell's Managing Director, Richard Caldwell was kind enough to talk with Perovskite-Info about the Company's current technology and future plans - and his views on the perovskite market.

EPFL researchers have shown that Incorporating guanidinium into perovskite solar cells stabilizes their efficiency at 19% for 1000 hours under full-sunlight testing conditions.

A major challenge in the PSCs field is stability; Unlike silicon cells, perovskites are soft crystalline materials and prone to problems due to decomposition over time. In a commercial context, this tends to inflate the costs of perovskite-based solar cells compared with conventional silicon cells. There have therefore been many efforts in synthesizing perovskite materials that can maintain high efficiency over time. This is done by introducing different cations (positively charged ions) into the crystal structure of the perovskite. Although success has been reported in several studies, these solutions can often be difficult and expensive to implement.

Emberion researchers have shown that colloidal quantum dots (QDs) combined with a graphene charge transducer can provide a photoconducting platform with high quantum efficiency and large intrinsic gain, yet compatible with cost-efficient polymer substrates. The team demonstrated methods to couple large QDs (>6 nm in diameter) with organometal halide perovskites, enabling hybrid graphene photo-transistor arrays on plastic foils.

The resulting arrays simultaneously exhibited a specific detectivity of 5 × 1012 Jones and high video-frame-rate performance. PbI2 and CH3NH3I co-mediated ligand exchange in PbS QDs improved surface passivation and facilitated electronic transport, yielding faster charge recovery, whereas PbS QDs embedded into a CH3NH3PbI3 matrix produce spatially separated photocarriers leading to large gain.

Greatcell Solar has announced that it has finalized and signed a funding agreement with the Australian Renewable Energy Agency (ARENA) for a 6 million AUD (around $4.5 million USD) grant under the Advancing Renewables Program (ARP). The grant will assist in developing a world-class prototype facility in Australia for the fabrication of high quality, large area, current generation and next generation perovskite devices, an essential prerequisite to large scale manufacture.

The grant will assist Greatcell to accelerate its scale-up and prototyping activities that are critical to its commercialization objectives, and is said to clearly demonstrate the importance of ARENA in supporting the development of renewable energy technology in Australia.