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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Solar Tarp – foldable, portable solar power.

California based Lipomi Research Group are working on creating a solar tarp – which would have myriad uses for society. Let’s learn more about how these upgraded solar panels could help parts of the world where they don’t have access to regular electricity – and some of the technological challenges they’re facing trying to complete the project.

About the Solar Tarp technology

Prototype Solar Tarp Sample - University of California
Prototype Solar Tarp Sample – University of California (source: theconversation.com)

The Lipomi Research Group are focused on “identifying ways to create materials with both good semiconducting properties and the durability plastics are known for – whether flexible or not”.  They’ve been tinkering with perovskite solar cells, which are 1/1000 the thickness of a silicon layer in a solar panel. 

Darren Lipomi of the Lipomi Group, who is also a Professor of Nanoengineering at the University of California, said that their goal is to create flexible solar panels which are as efficient as conventional silicon but don’t have some of the drawbacks of it.

The goal is to develop flexible solar panels which are thin, lightweight, and bendable. Lipomi is calling their idea a ‘solar tarp’ – which refers to a solar panel which can be expanded to the ‘size of a room’, but balled up to the size of a grapefruit when not in use. The issues here are finding a molecular structure to make the solar panels stretchable and tough – this involves replacing the silicon semiconductors with materials such as perovskite. 

They’re also taking a look at polymer semiconductors / organic semiconductors (based on carbon, and used in place of perovskites or silicon in a solar cell). These aren’t as efficient, but are far more flexible and extremely durable.

According to The Conversation, the sunlight that hits the earth in a single hour contains more energy than the whole planet uses in an entire year – so there’s plenty more work to do on improving how we utilise the sun! We’ll keep an eye on the solar tarp project and let you know when it reaches the next stage.

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ClearVue Technologies Solar Glass/Windows IPO

Western Australian solar glass company ClearVue Technologies are preparing to float on the ASX – in order to raise capital to sell their solar power generating glass windows globally. They’ve developed the tech in conjunction with the Electron Science Research Institute (ESRI) at Edith Cowan University. 

ClearVue Technologies

According to an interview with Finance News Network, ClearVue’s executive chairman Victor Rosenberg said the company is currently in the pre-development stage and are hoping to commence manufacturing the windows within the next 8 weeks.  They have a manufacturing partner in China called ROCKY Glass who will be making the windows to start, then they will licence the product worldwide, gaining income from both licensing and royalties. 

The ClearVue website have discussed their plans for the future: “Our technology presents a paradigm shift in the way glass will be used in building construction, automobiles, agriculture and speciality products”. 

ClearVue, founded in 1995, have lodged with ASIC to apply for 25,000,000 Shares at an issue price of $0.20 per Share to raise $5,000,000. Click here to download their prospectus and apply for shares online if you’re interested in their IPO. 

Solar Windows and Solar Glass

ClearVue Technologies Solar Glass and Windows
ClearVue Technologies Solar Glass and Windows (source: http://www.clearvuepv.com/)

ClearVue Technologies’ current offering is a patented nano technology – using BIPV (Building-Integrated Photovoltaic). Unlike most of their competitors the window remains clear, and the solar glass also “allows the visible light to pass through up to 70 per cent and it rejects the infrared and the UV from penetrating the room”. 

“Nobody actually has got clear glass,” said Rosenberg in an interview last year.  “They’ve got either lines or they’ve got dots, or looks like a chessboard with squares of solar panels on the glass.

“We are today, I would proudly say, the only commercial-size clear glass super building material producer.”

The windows currently generate 30W per square metre whilst simultaneously insulating and providing UV control. They’re hoping to reach 50W per square metre as they improve the BIPV technology. 

We’ve written quite extensively on solar windows – with technology such as perovskite solar cells and inkjet printed solar cells using Cyanobacteria among the more interesting ideas. There’s no doubt that this will be a huge market and there are quite a lot of competitors jostling to bring the best technology to market, so it’ll be exciting to see what happens!

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Perovskite Degradation – Major Breakthrough

Scientists the world over have been trying to create inexpensive, highly efficient solar cells out of perovskite, and this week some new research has come out which moves us another step in that direction. Perovskite degradation occurs rapidly when the naturally occurring mineral exposed to ambient air, which is quite the issue for a solar cell. According to the NREL team,Researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have manufactured an environmentally stable, high-efficiency perovskite solar cell. Another step closer to commercial sale of perovskite solar cells!

Perovskite Degradation and the NREL Research

Perovskite Degradation
Perovskite Degradation (source: wikipedia.org)

CleanTechnica have written an article about the NREL Research on perovskite deterioration in ambient air and are reporting that the research team have successfully tested a perovskite solar cell in ambient conditions with no protection for 1,000 hours – with a fantastic result that 94% of conversion efficiency was retained.

The scope of the research is a little over our head, but if you’re interested in learning more about the study “Tailored Interfaces of Unencapsulated Perovskite Solar Cells for >1000 Hours of Ambient Operational Stability you can click the link to read about it via Nature magazine. 

In simplest form, previous methods of protecting the perovskite have focused on creating a protective enclosure around the solar cell. Instead of that, they focused on the ‘weakest link’ in a perovskite solar cell and replaced it with a different molecule.

“Each interface and contact layer throughout the device stack plays an important role in the overall stability which, when appropriately modified, yields devices in which both the initial rapid decay (often termed burn-in) and the gradual slower decay are suppressed.”

Perovskite research is moving along at a fantastic clip. Here are some other updates on this technology we’re really excited about:

 

 

 

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