Doping Solar Cells | Perovskite Tech Upgrade!

Doping solar cells – Swinburne University have been making big improvements on their research in upgrading efficiency of perovskite solar cells. Let’s read more.

Doping Solar Cells | Perovskite Tech Upgrade!

Swinburne University have been working in conjunction with Wuhan University of Technology in China, the University of Melbourne, and the University of Adelaide. Their research is to do with ‘doping solar cells’ – using sunlight as a ‘healing process’ to improve cell efficiency and stability. ‘Doping’ perovskite solar cells with potassium is having a big effect on increasing stability and efficiency of the solar cells. 

We’ve written extensively about the potential that perovskite solar cells could have – potentially overcoming Shockley–Queisser limit (33.7% at 1.34 eV) means that the theoretical conversion limit silicon based solar cells has could be improved upon.

As per Wikipedia, Perovskite tech has been moving along in leaps and bounds over the past 5 years:

Solar cell efficiencies of devices using these materials have increased from 3.8% in 2009[3] to 24.2% in 2019 in single-junction architectures,[4] and, in silicon-based tandem cells, to 28.0%,[4] exceeding the maximum efficiency achieved in single-junction silicon solar cells.

With the potassium ‘doping’, the sunlight starts to repair ‘interface traps’:

“Sunlight becomes a trigger for the positive formation of potassium bromide-like compounds, eliminating the interface traps and stabilising the mobile ions, thus resulting in improved power conversion efficiency,” Dr Weijian Chen, an early career researcher at Swinburne, noted in comments on the Swinburne website.

“This research contributes to the rationalisation of the improved performance and guides future design protocol of better solar cells.” Dr Xiaoming Wen, senior research fellow at Swinburne continued.

“The demonstrated solar cell characterisation methods are at the cutting edge, and will help our industry partners develop a new protocol for commercial perovskite solar cells.” Director of Swinburne’s newly founded Centre of Translational Atomaterials (CTAM), Professor Baohua Jia said about the technology.

If you’d like to read more, the research, funded by the Australian Research Council under the Discovery Project program, has been published in Advanced Energy Materials.

 

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GreatCell Solar Enters Administration

Last month one of Australia’s longest running solar tech companies, GreatCell Solar, went into administration after the double blow of the death of their lead scientist and a failure to secure funding for its Dye Solar Cells prototype facility. 

GreatCell Solar Calls In Administrators

GreatCell Solar have unfrotunately had to call in administrators in December 2018 due to the death of their chief scientist and a problem with funding.

“The decision follows a series of unfortunate and unwelcome developments in recent weeks, including the untimely death of chief scientist Dr Hans Desilvestro in a mountaineering accident on 10 November,” Greatcell (ASX:GSL) told investors in mid-December. 

According to Stockhead, GreatCell has developed a third generation photovoltaic (PV) technology called Dye Solar Cells (DSC). DSCs are based on dye-sensitised films and are able to convert any visible light (including indoor low light) into electricity. They have been trying to get more funding for the tech but they’ve had problems with that too.

GreatCell Funding Fail

“Despite a global search and chasing down every potential funding opportunity, GSL has not been able to attract sufficient long-term equity investment,” the solar company said in a statement published on RenewEconomy:

“This is an extremely disappointing outcome for Greatcell Solar, its directors, employees and shareholders given the considerable investment already undertaken over many years to achieve an advanced, pre-commercialisation status for its 3rd generation photovoltaic technology.

“The Company is widely considered amongst its international peers to be pre-eminent in the field of Perovskite Solar Cell PV technology” the statement continues.

In late 2007 GreatCell were the recipients of a $6m ARENA grant to help fund research into perovskite solar cell technology. Unfortunately it appears that they’re somewhat stymied at the moment – but they still have a tech roadmap up on their website which leads us to still have some hope:

GreatCell Solar
GreatCell Solar Technology Roadmap (source: greatcellsolar.com.au)

Perovskite solar cells are gaining traction lately and this is the tech used in these prototypes. No word yet on what’s going to happen to Greatcell in 2019, but its statement didn’t leave a surfeit of hope: 

“With the appointment of Administrators, BRI Ferrier, the outlook for shareholders is uncertain at best” it reads. Fingers crossed they’re able to secure some more funding and get back to work with a new team. 

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Greatcell Get $6m Perovskite Solar Cell research.

Greatcell Solar has been awarded a grant by ARENA (Australian Renewable Energy Agency) to continue their research into producing perovskite cells for solar power generation. We’ve written about perovskite solar cells a few times this year – with the technology showing great potential and shaping up as an inexpensive alternative to conventional silicon cell technology. 

Greatcell and Perovskite

Queanbeyan-based Greatcell, formerly Dyesol, will spend $17.3m on developing a world-class plant which will scale up their manufacturing capability of high quality, large-area perovskite devices. ARENA will fund $6m of the project following a successful previous grant of $450,000 to continue work on the technology.   

ARENA CEO Ivor Frischknecht released a statement on Tuesday about the second grant: 

“This has the potential to expand the applications for which solar can be used and to reduce costs,” Frischknecht said.

“We want to move perovskites closer towards commercialisation. This will help accelerate solar PV innovation in Australia, which is one of our key priorities.”

Greatcell Solar MD Richard Caldwell told RenewEconomy that they are confident in the long-term viability of perovskite in practical situations in the near future: 

“It has the compelling attributes of lower cost and greater versatility than existing PV technologies. In particular, it is suited to real world solar conditions,” 

“In the long term, this technology has the potential to provide a cost competitive and clean energy solution,” Caldwell was quoted as saying. 

Greatcell and Jinko Solar

Greatcell signed an MoU (Memorandum of Understanding) with Jinko Solar earlier this year, which gives Jinko access to Greatcell’s perovskite solar technology. Their goal is to partner up and start manufacturing and selling perovskite-based solar on a large scale. 

Perovskite solar cells and Guanidinium

Greatcell Perovskite Solar Cells
Greatcell Solar Research into Perovskite (source: wikipedia.org)

According to Nature Energy, there’s been another breakthrough with the perovskite cells – incorporating the large organic cation guanidinium (CH6N3+) into methylammonium lead iodide perovskites has helped improving the stability of the perovskites (which are prone to decomposing over time – one of the main problems researchers are facing). 

With the addition of the guanidinium, perovskite solar cells are already working at 19% efficiency for 1000 hours under full-sunlight testing conditions – with silicon solar cells plateauing at around 25% due to the Shockley-Queisser limit. For that reason, we’re pouring money into finding an alternative to silicon solar cells – and it looks like perovskite has the potential to take over. Exciting times – watch this space and we’ll continue following the research and keeping you updated! 

 

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Perovskite Solar Cell Efficiency

Perovskite solar cell research is continuing at a fantastic rate, with the March issue of academic journal Science reporting that a collaboration between UNIST (Ulsan National Institute of Science and Technology) and the Korean Research Institute of Chemical Technology (KRICT) was able to reach 21.2% efficiency with a hybrid organic/inorganic perovskite solar cell.

Perovskite (wiki), a raw material which can be used to harvest solar energy and can be combined with liquid solutions to allow broad application (i.e. the conventional rigid shape of the solar panel could be superseded by something like a ‘spray’ application of a perovskite-based solution), is paving the way for solar technology. Researchers at the ANU (Australian National University) have achieved 26.4% efficiency using a stacked configuration of silicon and perovskite solar cells. The Duong from ANU’s Research School of Engineering heralded the achievement as ‘…a step closer to a low-cost alternative (to silicon based cells)’. It’s important to note that this efficiency was created ANU’s cell size was 0.18cm² (a research size – far from commercially viable). UNSW achieved 12% efficiency for a ‘full size’ 16cm² solar cell last December. Solliance, a Dutch/German/Belgian R&D team, achieved 12.6% in R2R (roll to roll) perovskite solar cells in March.

Perovskite Solar
Perovskite (image: Wikipedia.com)

Although still a far way from the 26.3% efficiency achieved by the Kaneka Corporation using silicon solar panels, it’s important to note that due to the Shockley-Queisser limit silicon panels will never reach greater than 1/3 efficiency. Using perovskite to manufacture solar cells could potentially double this limit – with the added bonus of being inexpensive and using less energy to manufacture. The hybrid organic/inorganic perovskite solar cell discussed at the start of this article (iodine/lead/methyl-ammonium crystalline structure) boosts the efficiency of the panel so that it can carry 2/3 of the energy from light without losing so much to heat.

The fact that this compound can also be applied through myriad techniques such as spraying, dipping, printing, and doctor-blading means that it has a much wider range of application. ‘Solar cells are no longer limited to rigid structures such as panels’, says Dr Anita Ho-baillie, head of Perovskite Solar Cell Research at the Australian Centre for Advanced Photovoltaics (ACAP) at UNSW.

Perovskite’s potential in terms of solar cells was first discovered by Japanese researchers in 2006 and Dr Ho-Baillie says she thinks perovskite solar cell efficiency will be able to reach 24% by the end of the year. There’s still a long way to go for perovskite to surpass silicon as the material of choice for solar cells, but progress is steady and as soon as they break the ‘magical’ 30% barrier it’ll become the material of choice for solar panels, if not before.

 

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